Polar coding techniques for blind detection of different payload sizes

ABSTRACT

Methods, systems, and devices for wireless communications are described. In some systems, wireless devices may encode and decode transmissions using polar codes. A transmitting device may encode a payload based on a selected payload size. For example, the transmitting device may construct a bit vector including payload bits, parity bits, frozen bits, or some combination of in these, and may modify the bits or the order of the bits based on the selected payload size. The device may generate a polar-encoded codeword based on this bit vector, and may transmit the polar-encoded codeword to a receiving device. The receiving device may blind decode the polar-encoded codeword, and may determine the correct payload size based on the decoded bit vector. For example, the device may perform decoding or may check decoded bits based on a payload size hypothesis, where the decoding may fail for any incorrect payload size hypothesis.

CROSS REFERENCES

The present Application is a 371 national phase of International PatentApplication No. PCT/CN2018/107179 by Qualcomm Incorporated et al.,entitled “POLAR CODING TECHNIQUES FOR BLIND DETECTION OF DIFFERENTPAYLOAD SIZES,” filed Sep. 24, 2018, which claims priority toInternational Patent Application No. PCT/CN2017/111600 by QualcommIncorporated et al., entitled “POLAR CODING TECHNIQUES FOR BLINDDETECTION OF DIFFERENT PAYLOAD SIZES,” filed Nov. 17, 2017, each ofwhich is assigned to the assignee hereof and expressly incorporated byreference herein in its entirety.

BACKGROUND

The following relates generally to wireless communication, and morespecifically to polar coding techniques for blind detection of differentpayload sizes.

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be capable ofsupporting communication with multiple users by sharing the availablesystem resources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include fourth generation (4G) systems such as aLong Term Evolution (LTE) systems or LTE-Advanced (LTE-A) systems, andfifth generation (5G) systems which may be referred to as New Radio (NR)systems. These systems may employ technologies such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), or discreteFourier transform-spread-orthogonal frequency-division multiplexing(OFDM) (DFT-S-OFDM). A wireless multiple-access communications systemmay include a number of base stations or network access nodes, eachsimultaneously supporting communication for multiple communicationdevices, which may be otherwise known as user equipment (UE).

In some wireless communications systems, wireless devices may implementerror-correcting codes, such as polar codes, to encode and decodetransmissions. A wireless device may transmit using multiple differentcodeword configurations, including the size of a payload encoded withinthe codeword, when implementing polar codes. However, encoding certainspecific payloads of different sizes may result in identical codewordsfor transmission. In these cases, a wireless device receiving one ofthese codewords may not be able to accurately determine the payload orpayload size, as the received codeword could map to multiple differentpayloads and corresponding payload sizes.

SUMMARY

The described techniques relate to improved methods, systems, devices,or apparatuses that support polar coding techniques for blind detectionof different payload sizes. Generally, the described techniques providefor encoding and decoding codewords using polar codes, where thecodewords indicate a payload size. A wireless device may select apayload (e.g., a set of payload bits) for transmission, and may encodethe payload based on the size of the payload. For example, thetransmitting device may construct a bit vector including payload bits,parity bits, frozen bits, or some combination of these bits, and maymodify the bits or the order of the bits in the bit vector based on theselected payload size. The device may generate a codeword based on thisbit vector and a polar code and may transmit the codeword to a receivingdevice. The receiving device may not know the payload size of thereceived codeword and may perform a blind decoding process to determinethe correct payload size. For example, the device may perform decodingor may check decoded bits for the codeword based on a payload sizehypothesis, where the decoding process may fail for any incorrectpayload size hypothesis. When a payload size hypothesis results in adecoded bit vector that passes the parity checks, the device maydetermine that the hypothesized payload size is correct, and may parsethe payload bits from the decoded bit vector to determine thetransmitted information.

A method of wireless communications is described. The method may includeidentifying a plurality of payload bits of a payload for encoding,determining a bit vector comprising the plurality of payload bits,wherein at least one bit or a bit order of the bit vector is based atleast in part on a size of the payload, generating a polar-encodedcodeword based at least in part on the bit vector, and transmitting thepolar-encoded codeword.

An apparatus for wireless communications is described. The apparatus mayinclude means for identifying a plurality of payload bits of a payloadfor encoding, means for determining a bit vector comprising theplurality of payload bits, wherein at least one bit or a bit order ofthe bit vector is based at least in part on a size of the payload, meansfor generating a polar-encoded codeword based at least in part on thebit vector, and means for transmitting the polar-encoded codeword.

Another apparatus for wireless communications is described. Theapparatus may include a processor, memory in electronic communicationwith the processor, and instructions stored in the memory. Theinstructions may be operable to cause the processor to identify aplurality of payload bits of a payload for encoding, determine a bitvector comprising the plurality of payload bits, wherein at least onebit or a bit order of the bit vector is based at least in part on a sizeof the payload, generate a polar-encoded codeword based at least in parton the bit vector, and transmit the polar-encoded codeword.

A non-transitory computer-readable medium for wireless communications isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to identify a plurality ofpayload bits of a payload for encoding, determine a bit vectorcomprising the plurality of payload bits, wherein at least one bit or abit order of the bit vector is based at least in part on a size of thepayload, generate a polar-encoded codeword based at least in part on thebit vector, and transmit the polar-encoded codeword.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for determining a masking vectorcorresponding to the size of the payload. Some examples of the method,apparatus, and non-transitory computer-readable medium described abovemay further include processes, features, means, or instructions forscrambling the plurality of payload bits, a plurality of parity bitsassociated with the plurality of payload bits, a plurality of frozenbits, or a combination thereof with the masking vector.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, scrambling the plurality ofpayload bits, the plurality of parity bits, the plurality of frozenbits, or the combination thereof with the masking vector comprises anexclusive or (XOR) operation.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the bit vector comprises theplurality of payload bits and a plurality of parity bits associated withthe plurality of payload bits. In some examples of the method,apparatus, and non-transitory computer-readable medium described above,determining the bit vector comprises positioning at least one bit of theplurality of parity bits in a lowest index of the bit vector, whereinthe plurality of payload bits may be positioned in higher indices of thebit vector.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, generating the polar-encodedcodeword comprises assigning the plurality of payload bits and theplurality of parity bits to a plurality of information bit channels of apolar code, wherein the at least one bit of the plurality of parity bitsmay be assigned to a least reliable channel of the plurality ofinformation bit channels.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for applying a parity function to theplurality of payload bits to generate the plurality of parity bits. Insome examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the plurality of parity bitscomprises a plurality of cyclic redundancy check (CRC) bits.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, determining the bit vectorcomprises appending an initial bit to the bit vector, wherein theinitial bit comprises an opposite bit value to a default frozen bitvalue. In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the initial bit indicates amessage type associated with the payload.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, determining the bit vectorcomprises arranging the plurality of payload bits, a plurality of paritybits associated with the plurality of payload bits, a plurality offrozen bits, or a combination thereof so that an initial bit of the bitvector comprises an opposite bit value to a default frozen bit value.

A method of wireless communications is described. The method may includereceiving a polar-encoded codeword, the polar-encoded codeword generatedbased at least in part on a bit vector comprising a plurality of payloadbits of a payload, and performing a blind decoding process on thepolar-encoded codeword, the blind decoding process comprising:determining a size of the payload based at least in part on at least onelog-likelihood ratio (LLR) associated with the bit vector; decoding thepolar-encoded codeword to obtain the bit vector based at least in parton the determined size of the payload; and parsing the bit vector toobtain the plurality of payload bits based at least in part on thedetermined size of the payload.

An apparatus for wireless communications is described. The apparatus mayinclude means for receiving a polar-encoded codeword, the polar-encodedcodeword generated based at least in part on a bit vector comprising aplurality of payload bits of a payload, and means for performing a blinddecoding process on the polar-encoded codeword, the blind decodingprocess comprising: means for determining a size of the payload based atleast in part on at least one LLR associated with the bit vector; meansfor decoding the polar-encoded codeword to obtain the bit vector basedat least in part on the determined size of the payload; and means forparsing the bit vector to obtain the plurality of payload bits based atleast in part on the determined size of the payload.

Another apparatus for wireless communications is described. Theapparatus may include a processor, memory in electronic communicationwith the processor, and instructions stored in the memory. Theinstructions may be operable to cause the processor to receive apolar-encoded codeword, the polar-encoded codeword generated based atleast in part on a bit vector comprising a plurality of payload bits ofa payload, and perform a blind decoding process on the polar-encodedcodeword, the instructions for the blind decoding process comprisingfurther instructions operable to cause the processor to: determine asize of the payload based at least in part on at least one LLRassociated with the bit vector; decode the polar-encoded codeword toobtain the bit vector based at least in part on the determined size ofthe payload; and parse the bit vector to obtain the plurality of payloadbits based at least in part on the determined size of the payload.

A non-transitory computer-readable medium for wireless communications isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to receive a polar-encodedcodeword, the polar-encoded codeword generated based at least in part ona bit vector comprising a plurality of payload bits of a payload, andperform a blind decoding process on the polar-encoded codeword, theinstructions for the blind decoding process comprising furtherinstructions operable to cause the processor to: determine a size of thepayload based at least in part on at least one LLR associated with thebit vector; decode the polar-encoded codeword to obtain the bit vectorbased at least in part on the determined size of the payload; and parsethe bit vector to obtain the plurality of payload bits based at least inpart on the determined size of the payload.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, determining the size of thepayload comprises performing one or more de-scrambling operations on atleast one bit decision for the at least one LLR, wherein eachde-scrambling operation utilizes a masking vector corresponding to apayload size.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying a successfulde-scrambling operation based at least in part on comparing a pluralityof de-scrambled parity bits to a plurality of de-scrambled payload bits.Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for determining the size of the payloadas the payload size corresponding to the masking vector for thesuccessful de-scrambling operation.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the de-scrambling operationcomprises an inverse XOR operation.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the polar-encoded codeword maybe further generated based at least in part on a plurality of paritybits, the plurality of payload bits and the plurality of parity bitsassigned to a plurality of information bit channels, and determining thesize of the payload comprises performing one or more parity checks on atleast one bit decision for the at least one LLR using the plurality ofparity bits, wherein a positioning of the plurality of parity bitswithin the polar-encoded codeword for each parity check indicates acorresponding payload size.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying a successful paritycheck based at least in part on the plurality of parity bits and the atleast one bit decision for the at least one LLR. Some examples of themethod, apparatus, and non-transitory computer-readable medium describedabove may further include processes, features, means, or instructionsfor determining the size of the payload as the corresponding payloadsize indicated by the positioning of the plurality of parity bitsresulting in the successful parity check.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, at least one bit of theplurality of parity bits may be assigned to a least reliable channel ofthe plurality of information bit channels. In some examples of themethod, apparatus, and non-transitory computer-readable medium describedabove, the plurality of parity bits comprises a plurality of CRC bits.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, determining the size of thepayload comprises identifying a least reliable bit channel of thepolar-encoded codeword with an LLR indicating an opposite bit value to adefault frozen bit value. Some examples of the method, apparatus, andnon-transitory computer-readable medium described above may furtherinclude processes, features, means, or instructions for determining thesize of the payload based at least in part on the identified leastreliable bit channel.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, parsing the bit vectorcomprises removing an initial bit corresponding to the LLR indicatingthe opposite bit value to the default frozen bit value.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, parsing the bit vectorcomprises reordering bits of the bit vector based at least in part onthe LLR indicating the opposite bit value to the default frozen bitvalue.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a device that supports polar codingtechniques for blind detection of different payload sizes in accordancewith aspects of the present disclosure.

FIG. 3 illustrates an example of a polar encoding process that supportspolar coding techniques for blind detection of different payload sizesin accordance with aspects of the present disclosure.

FIGS. 4A, 4B, and 4C illustrate examples of payload size indicationsthat support polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.

FIG. 5 illustrates an example of a process flow that supports polarcoding techniques for blind detection of different payload sizes inaccordance with aspects of the present disclosure.

FIGS. 6 and 7 show block diagrams of a device that supports polar codingtechniques for blind detection of different payload sizes in accordancewith aspects of the present disclosure.

FIG. 8 shows a block diagram of an encoder polar coding module thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.

FIG. 9 shows a block diagram of a system including a device thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.

FIGS. 10 and 11 show block diagrams of wireless devices that supportpolar coding techniques for blind detection of different payload sizesin accordance with aspects of the present disclosure.

FIG. 12 shows a block diagram of a decoder polar coding module thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.

FIG. 13 illustrates a block diagram of a system including a decoder thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.

FIGS. 14 through 19 show flowcharts illustrating methods for polarcoding techniques for blind detection of different payload sizes inaccordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless communications systems, wireless devices (e.g., basestations or user equipments (UEs)) may implement polar codes to encodeand decode transmissions. In some cases, a transmitting device mayselect a payload for transmission. The size of the payload may beconfigurable, for example, from a list of possible payload sizes. Insome cases, the transmitting device may implement one or more techniquesto indicate the selected payload size to a device decoding the codeword.These techniques may result in a unique codeword for any payload, sothat a device blind decoding the codeword may correctly determine theencoded payload. For example, a receiving device may monitor forcodewords generated using any of the possible payload sizes. Thereceiving device may implement one or more techniques corresponding tothe techniques utilized by the transmitting device in order to determinethe payload size of a codeword.

To perform these techniques, the transmitting device may determine a setof information bits for encoding, where the information bits may includethe payload bits and parity bits generated based on the payload bits.These information bits may be organized into a bit vector. Thetransmitting device may modify the bit vector based on the size of thepayload (e.g., the number of payload bits). In a first technique, thetransmitting device may determine a masking vector corresponding to thepayload size (e.g., from a table in memory or based on an equation). Thedevice may mask or scramble one or more bits of the bit vector using themasking vector. In a second technique, the device may position at leasta portion of the parity bits in the bit vector at lower bit indices thanthe payload bits. In a third technique, the device may ensure that thefirst bit index of the bit vector contains a different bit value thanthat of a default frozen bit value (e.g., if frozen bits have defaultvalues of 0, the first bit index will have a bit value of 1). Forexample, the device may insert an additional bit at the first bit indexof the bit vector, or may arrange the payload bits so that the first bitwill be a 1 bit. In some cases, the bit vector described above may bereferred to as an information bit vector and may be a portion of alarger bit vector. This larger bit vector may additionally include a setof frozen bits in lower bit indices than the information bit vector. Thetransmitting device may assign the bits of the bit vector tocorresponding bit channels (e.g., assigning each bit of the bit vectorin increasing index order to a bit channel in order of increasingchannel reliability), and may generate a codeword using the assigned bitchannels and a polar code. The device may transmit this generatedcodeword to a receiving device.

The receiving device may decode the codeword using a blind decodingprocess. For example, the receiving device may decode the receivedsignal using one or more hypotheses for the payload size. For each ofthe techniques described above, the decoding process may fail if thereceiving device assumes an incorrect payload size hypothesis. Forexample, in the first two techniques, a parity check or cyclicredundancy check (CRC) may fail if the codeword is decoded using anincorrect masking vector or an incorrect starting position for the CRC.In the third technique, the receiving device may determine the positionof the first information bit within the bit vector, as this firstinformation bit will be the first bit with a value different than thedefault frozen bit value. Using one or more of these techniques, thereceiving device may successfully decode codewords of different payloadsizes.

Aspects of the disclosure are initially described in the context of awireless communications system. Additional aspects are described withrespect to a polar coding device, an encoding process, payload sizeindications, and a process flow. Aspects of the disclosure are furtherillustrated by and described with reference to apparatus diagrams,system diagrams, and flowcharts that relate to polar coding techniquesfor blind detection of different payload sizes.

FIG. 1 illustrates an example of a wireless communications system 100that supports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure. Thewireless communications system 100 includes base stations 105, UEs 115,and a core network 130. In some examples, the wireless communicationssystem 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced(LTE-A) network, or a New Radio (NR) network. In some cases, wirelesscommunications system 100 may support enhanced broadband communications,ultra-reliable (e.g., mission critical) communications, low latencycommunications, or communications with low-cost and low-complexitydevices. In some cases, the wireless devices of wireless communicationssystem 100 (e.g., base stations 105 and UEs 115) may utilize polarcoding techniques.

Base stations 105 may wirelessly communicate with UEs 115 via one ormore base station antennas. Base stations 105 described herein mayinclude or may be referred to by those skilled in the art as a basetransceiver station, a radio base station, an access point, a radiotransceiver, a NodeB, an eNodeB (eNB), a next-generation Node B orgiga-nodeB (either of which may be referred to as a gNB), a Home NodeB,a Home eNodeB, or some other suitable terminology. Wirelesscommunications system 100 may include base stations 105 of differenttypes (e.g., macro or small cell base stations). The UEs 115 describedherein may be able to communicate with various types of base stations105 and network equipment including macro eNBs, small cell eNBs, gNBs,relay base stations, and the like.

Each base station 105 may be associated with a particular geographiccoverage area 110 in which communications with various UEs 115 issupported. Each base station 105 may provide communication coverage fora respective geographic coverage area 110 via communication links 125,and communication links 125 between a base station 105 and a UE 115 mayutilize one or more carriers. Communication links 125 shown in wirelesscommunications system 100 may include uplink transmissions from a UE 115to a base station 105, or downlink transmissions, from a base station105 to a UE 115. Downlink transmissions may also be called forward linktransmissions while uplink transmissions may also be called reverse linktransmissions.

The geographic coverage area 110 for a base station 105 may be dividedinto sectors making up only a portion of the geographic coverage area110, and each sector may be associated with a cell. For example, eachbase station 105 may provide communication coverage for a macro cell, asmall cell, a hot spot, or other types of cells, or various combinationsthereof. In some examples, a base station 105 may be movable andtherefore provide communication coverage for a moving geographiccoverage area 110. In some examples, different geographic coverage areas110 associated with different technologies may overlap, and overlappinggeographic coverage areas 110 associated with different technologies maybe supported by the same base station 105 or by different base stations105. The wireless communications system 100 may include, for example, aheterogeneous LTE/LTE-A or NR network in which different types of basestations 105 provide coverage for various geographic coverage areas 110.

The term “cell” refers to a logical communication entity used forcommunication with a base station 105 (e.g., over a carrier), and may beassociated with an identifier for distinguishing neighboring cells(e.g., a physical cell identifier (PCID), a virtual cell identifier(VCID)) operating via the same or a different carrier. In some examples,a carrier may support multiple cells, and different cells may beconfigured according to different protocol types (e.g., machine-typecommunication (MTC), narrowband Internet-of-Things (NB-IoT), enhancedmobile broadband (eMBB), or others) that may provide access fordifferent types of devices. In some cases, the term “cell” may refer toa portion of a geographic coverage area 110 (e.g., a sector) over whichthe logical entity operates.

UEs 115 may be dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may also bereferred to as a mobile device, a wireless device, a remote device, ahandheld device, or a subscriber device, or some other suitableterminology, where the “device” may also be referred to as a unit, astation, a terminal, or a client. A UE 115 may also be a personalelectronic device such as a cellular phone, a personal digital assistant(PDA), a tablet computer, a laptop computer, or a personal computer. Insome examples, a UE 115 may also refer to a wireless local loop (WLL)station, an Internet of Things (IoT) device, an Internet of Everything(IoE) device, or an MTC device, or the like, which may be implemented invarious articles such as appliances, vehicles, meters, or the like.

Some UEs 115, such as MTC or IoT devices, may be low cost or lowcomplexity devices, and may provide for automated communication betweenmachines (e.g., via Machine-to-Machine (M2M) communication). M2Mcommunication or MTC may refer to data communication technologies thatallow devices to communicate with one another or a base station 105without human intervention. In some examples, M2M communication or MTCmay include communications from devices that integrate sensors or metersto measure or capture information and relay that information to acentral server or application program that can make use of theinformation or present the information to humans interacting with theprogram or application. Some UEs 115 may be designed to collectinformation or enable automated behavior of machines. Examples ofapplications for MTC devices include smart metering, inventorymonitoring, water level monitoring, equipment monitoring, healthcaremonitoring, wildlife monitoring, weather and geological eventmonitoring, fleet management and tracking, remote security sensing,physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reducepower consumption, such as half-duplex communications (e.g., a mode thatsupports one-way communication via transmission or reception, but nottransmission and reception simultaneously). In some examples half-duplexcommunications may be performed at a reduced peak rate. Other powerconservation techniques for UEs 115 include entering a power saving“deep sleep” mode when not engaging in active communications, oroperating over a limited bandwidth (e.g., according to narrowbandcommunications). In some cases, UEs 115 may be designed to supportcritical functions (e.g., mission critical functions), and a wirelesscommunications system 100 may be configured to provide ultra-reliablecommunications for these functions.

In some cases, a UE 115 may also be able to communicate directly withother UEs 115 (e.g., using a peer-to-peer (P2P) or device-to-device(D2D) protocol). One or more of a group of UEs 115 utilizing D2Dcommunications may be within the geographic coverage area 110 of a basestation 105. Other UEs 115 in such a group may be outside the geographiccoverage area 110 of a base station 105, or be otherwise unable toreceive transmissions from a base station 105. In some cases, groups ofUEs 115 communicating via D2D communications may utilize a one-to-many(1:M) system in which each UE 115 transmits to every other UE 115 in thegroup. In some cases, a base station 105 facilitates the scheduling ofresources for D2D communications. In other cases, D2D communications arecarried out between UEs 115 without the involvement of a base station105.

Base stations 105 may communicate with the core network 130 and with oneanother. For example, base stations 105 may interface with the corenetwork 130 through backhaul links 132 (e.g., via an S1 or otherinterface). Base stations 105 may communicate with one another overbackhaul links 134 (e.g., via an X2 or other interface) either directly(e.g., directly between base stations 105) or indirectly (e.g., via corenetwork 130).

The core network 130 may provide user authentication, accessauthorization, tracking, Internet Protocol (IP) connectivity, and otheraccess, routing, or mobility functions. The core network 130 may be anevolved packet core (EPC), which may include at least one mobilitymanagement entity (MME), at least one serving gateway (S-GW), and atleast one Packet Data Network (PDN) gateway (P-GW). The MME may managenon-access stratum (e.g., control plane) functions such as mobility,authentication, and bearer management for UEs 115 served by basestations 105 associated with the EPC. User IP packets may be transferredthrough the S-GW, which itself may be connected to the P-GW. The P-GWmay provide IP address allocation as well as other functions. The P-GWmay be connected to the network operators IP services. The operators IPservices may include access to the Internet, Intranet(s), an IPMultimedia Subsystem (IMS), or a Packet-Switched (PS) Streaming Service.

At least some of the network devices, such as a base station 105, mayinclude subcomponents such as an access network entity, which may be anexample of an access node controller (ANC). Each access network entitymay communicate with UEs 115 through a number of other access networktransmission entities, which may be referred to as a radio head, a smartradio head, or a transmission/reception point (TRP). In someconfigurations, various functions of each access network entity or basestation 105 may be distributed across various network devices (e.g.,radio heads and access network controllers) or consolidated into asingle network device (e.g., a base station 105).

Wireless communications system 100 may operate using one or morefrequency bands, typically in the range of 300 MHz to 300 GHz.Generally, the region from 300 MHz to 3 GHz is known as the ultra-highfrequency (UHF) region or decimeter band, since the wavelengths rangefrom approximately one decimeter to one meter in length. UHF waves maybe blocked or redirected by buildings and environmental features.However, the waves may penetrate structures sufficiently for a macrocell to provide service to UEs 115 located indoors. Transmission of UHFwaves may be associated with smaller antennas and shorter range (e.g.,less than 100 km) compared to transmission using the smaller frequenciesand longer waves of the high frequency (HF) or very high frequency (VHF)portion of the spectrum below 300 MHz.

Wireless communications system 100 may also operate in a super highfrequency (SHF) region using frequency bands from 3 GHz to 30 GHz, alsoknown as the centimeter band. The SHF region includes bands such as the5 GHz industrial, scientific, and medical (ISM) bands, which may be usedopportunistically by devices that can tolerate interference from otherusers.

Wireless communications system 100 may also operate in an extremely highfrequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz),also known as the millimeter band. In some examples, wirelesscommunications system 100 may support millimeter wave (mmW)communications between UEs 115 and base stations 105, and EHF antennasof the respective devices may be even smaller and more closely spacedthan UHF antennas. In some cases, this may facilitate use of antennaarrays within a UE 115. However, the propagation of EHF transmissionsmay be subject to even greater atmospheric attenuation and shorter rangethan SHF or UHF transmissions. Techniques disclosed herein may beemployed across transmissions that use one or more different frequencyregions, and designated use of bands across these frequency regions maydiffer by country or regulating body.

In some cases, wireless communications system 100 may utilize bothlicensed and unlicensed radio frequency spectrum bands. For example,wireless communications system 100 may employ License Assisted Access(LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technologyin an unlicensed band such as the 5 GHz ISM band. When operating inunlicensed radio frequency spectrum bands, wireless devices such as basestations 105 and UEs 115 may employ listen-before-talk (LBT) proceduresto ensure a frequency channel is clear before transmitting data. In somecases, operations in unlicensed bands may be based on a CA configurationin conjunction with CCs operating in a licensed band (e.g., LAA).Operations in unlicensed spectrum may include downlink transmissions,uplink transmissions, peer-to-peer transmissions, or a combination ofthese. Duplexing in unlicensed spectrum may be based on frequencydivision duplexing (FDD), time division duplexing (TDD), or acombination of both.

In some examples, base station 105 or UE 115 may be equipped withmultiple antennas, which may be used to employ techniques such astransmit diversity, receive diversity, multiple-input multiple-output(MIMO) communications, or beamforming. For example, wirelesscommunications system 100 may use a transmission scheme between atransmitting device (e.g., a base station 105) and a receiving device(e.g., a UE 115), where the transmitting device is equipped withmultiple antennas and the receiving devices are equipped with one ormore antennas. MIMO communications may employ multipath signalpropagation to increase the spectral efficiency by transmitting orreceiving multiple signals via different spatial layers, which may bereferred to as spatial multiplexing. The multiple signals may, forexample, be transmitted by the transmitting device via differentantennas or different combinations of antennas. Likewise, the multiplesignals may be received by the receiving device via different antennasor different combinations of antennas. Each of the multiple signals maybe referred to as a separate spatial stream, and may carry bitsassociated with the same data stream (e.g., the same codeword) ordifferent data streams. Different spatial layers may be associated withdifferent antenna ports used for channel measurement and reporting. MIMOtechniques include single-user MIMO (SU-MIMO) where multiple spatiallayers are transmitted to the same receiving device, and multiple-userMIMO (MU-MIMO) where multiple spatial layers are transmitted to multipledevices.

Beamforming, which may also be referred to as spatial filtering,directional transmission, or directional reception, is a signalprocessing technique that may be used at a transmitting device or areceiving device (e.g., a base station 105 or a UE 115) to shape orsteer an antenna beam (e.g., a transmit beam or receive beam) along aspatial path between the transmitting device and the receiving device.Beamforming may be achieved by combining the signals communicated viaantenna elements of an antenna array such that signals propagating atparticular orientations with respect to an antenna array experienceconstructive interference while others experience destructiveinterference. The adjustment of signals communicated via the antennaelements may include a transmitting device or a receiving deviceapplying certain amplitude and phase offsets to signals carried via eachof the antenna elements associated with the device. The adjustmentsassociated with each of the antenna elements may be defined by abeamforming weight set associated with a particular orientation (e.g.,with respect to the antenna array of the transmitting device orreceiving device, or with respect to some other orientation).

In one example, a base station 105 may use multiple antennas or antennaarrays to conduct beamforming operations for directional communicationswith a UE 115. For instance, some signals (e.g. synchronization signals,reference signals, beam selection signals, or other control signals) maybe transmitted by a base station 105 multiple times in differentdirections, which may include a signal being transmitted according todifferent beamforming weight sets associated with different directionsof transmission. Transmissions in different beam directions may be usedto identify (e.g., by the base station 105 or a receiving device, suchas a UE 115) a beam direction for subsequent transmission and/orreception by the base station 105. Some signals, such as data signalsassociated with a particular receiving device, may be transmitted by abase station 105 in a single beam direction (e.g., a directionassociated with the receiving device, such as a UE 115). In someexamples, the beam direction associated with transmissions along asingle beam direction may be determined based at least in in part on asignal that was transmitted in different beam directions. For example, aUE 115 may receive one or more of the signals transmitted by the basestation 105 in different directions, and the UE 115 may report to thebase station 105 an indication of the signal it received with a highestsignal quality, or an otherwise acceptable signal quality. Althoughthese techniques are described with reference to signals transmitted inone or more directions by a base station 105, a UE 115 may employsimilar techniques for transmitting signals multiple times in differentdirections (e.g., for identifying a beam direction for subsequenttransmission or reception by the UE 115), or transmitting a signal in asingle direction (e.g., for transmitting data to a receiving device).

A receiving device (e.g., a UE 115, which may be an example of a mmWreceiving device) may try multiple receive beams when receiving varioussignals from the base station 105, such as synchronization signals,reference signals, beam selection signals, or other control signals. Forexample, a receiving device may try multiple receive directions byreceiving via different antenna subarrays, by processing receivedsignals according to different antenna subarrays, by receiving accordingto different receive beamforming weight sets applied to signals receivedat a plurality of antenna elements of an antenna array, or by processingreceived signals according to different receive beamforming weight setsapplied to signals received at a plurality of antenna elements of anantenna array, any of which may be referred to as “listening” accordingto different receive beams or receive directions. In some examples areceiving device may use a single receive beam to receive along a singlebeam direction (e.g., when receiving a data signal). The single receivebeam may be aligned in a beam direction determined based at least inpart on listening according to different receive beam directions (e.g.,a beam direction determined to have a highest signal strength, highestsignal-to-noise ratio, or otherwise acceptable signal quality based atleast in part on listening according to multiple beam directions).

In some cases, the antennas of a base station 105 or UE 115 may belocated within one or more antenna arrays, which may support MIMOoperations, or transmit or receive beamforming. For example, one or morebase station antennas or antenna arrays may be co-located at an antennaassembly, such as an antenna tower. In some cases, antennas or antennaarrays associated with a base station 105 may be located in diversegeographic locations. A base station 105 may have an antenna array witha number of rows and columns of antenna ports that the base station 105may use to support beamforming of communications with a UE 115.Likewise, a UE 115 may have one or more antenna arrays that may supportvarious MIMO or beamforming operations.

In some cases, wireless communications system 100 may be a packet-basednetwork that operate according to a layered protocol stack. In the userplane, communications at the bearer or Packet Data Convergence Protocol(PDCP) layer may be IP-based. A Radio Link Control (RLC) layer may insome cases perform packet segmentation and reassembly to communicateover logical channels. A Medium Access Control (MAC) layer may performpriority handling and multiplexing of logical channels into transportchannels. The MAC layer may also use hybrid automatic repeat request(HARQ) to provide retransmission at the MAC layer to improve linkefficiency. In the control plane, the Radio Resource Control (RRC)protocol layer may provide establishment, configuration, and maintenanceof an RRC connection between a UE 115 and a base station 105 or corenetwork 130 supporting radio bearers for user plane data. At thePhysical (PHY) layer, transport channels may be mapped to physicalchannels.

In some cases, UEs 115 and base stations 105 may support retransmissionsof data to increase the likelihood that data is received successfully.HARQ feedback is one technique of increasing the likelihood that data isreceived correctly over a communication link 125. HARQ may include acombination of error detection (e.g., using a CRC), forward errorcorrection (FEC), and retransmission (e.g., automatic repeat request(ARQ)). HARQ may improve throughput at the MAC layer in poor radioconditions (e.g., signal-to-noise conditions). In some cases, a wirelessdevice may support same-slot HARQ feedback, where the device may provideHARQ feedback in a specific slot for data received in a previous symbolin the slot. In other cases, the device may provide HARQ feedback in asubsequent slot, or according to some other time interval.

Time intervals in LTE or NR may be expressed in multiples of a basictime unit, which may, for example, refer to a sampling period ofT_(s)=1/30,720,000 seconds. Time intervals of a communications resourcemay be organized according to radio frames each having a duration of 10milliseconds (ms), where the frame period may be expressed asT_(f)=307,200 T_(s). The radio frames may be identified by a systemframe number (SFN) ranging from 0 to 1023. Each frame may include 10subframes numbered from 0 to 9, and each subframe may have a duration of1 ms. A subframe may be further divided into 2 slots each having aduration of 0.5 ms, and each slot may contain 6 or 7 modulation symbolperiods (e.g., depending on the length of the cyclic prefix prepended toeach symbol period). Excluding the cyclic prefix, each symbol period maycontain 2048 sampling periods. In some cases a subframe may be thesmallest scheduling unit of the wireless communications system 100, andmay be referred to as a transmission time interval (TTI). In othercases, a smallest scheduling unit of the wireless communications system100 may be shorter than a subframe or may be dynamically selected (e.g.,in bursts of shortened TTIs (sTTIs) or in selected component carriersusing sTTIs).

In some wireless communications systems, a slot may further be dividedinto multiple mini-slots containing one or more symbols. In someinstances, a symbol of a mini-slot or a mini-slot may be the smallestunit of scheduling. Each symbol may vary in duration depending on thesubcarrier spacing or frequency band of operation, for example. Further,some wireless communications systems may implement slot aggregation inwhich multiple slots or mini-slots are aggregated together and used forcommunication between a UE 115 and a base station 105.

The term “carrier” refers to a set of radio frequency spectrum resourceshaving a defined physical layer structure for supporting communicationsover a communication link 125. For example, a carrier of a communicationlink 125 may include a portion of a radio frequency spectrum band thatis operated according to physical layer channels for a given radioaccess technology. Each physical layer channel may carry user data,control information, or other signaling. A carrier may be associatedwith a pre-defined frequency channel (e.g., an Evolved UniversalTerrestrial Radio Access (UTRA) (E-UTRA) absolute radio frequencychannel number (EARFCN)), and may be positioned according to a channelraster for discovery by UEs 115. Carriers may be downlink or uplink(e.g., in an FDD mode), or be configured to carry downlink and uplinkcommunications (e.g., in a TDD mode). In some examples, signal waveformstransmitted over a carrier may be made up of multiple sub-carriers(e.g., using multi-carrier modulation (MCM) techniques such asorthogonal frequency-division multiplexing (OFDM) or discrete Fouriertransform-spread OFDM (DFT-s-OFDM).

The organizational structure of the carriers may be different fordifferent radio access technologies (e.g., LTE, LTE-A, NR, etc.). Forexample, communications over a carrier may be organized according toTTIs or slots, each of which may include user data as well as controlinformation or signaling to support decoding the user data. A carriermay also include dedicated acquisition signaling (e.g., synchronizationsignals or system information, etc.) and control signaling thatcoordinates operation for the carrier. In some examples (e.g., in acarrier aggregation configuration), a carrier may also have acquisitionsignaling or control signaling that coordinates operations for othercarriers.

Physical channels may be multiplexed on a carrier according to varioustechniques. A physical control channel and a physical data channel maybe multiplexed on a downlink carrier, for example, using time divisionmultiplexing (TDM) techniques, frequency division multiplexing (FDM)techniques, or hybrid TDM-FDM techniques. In some examples, controlinformation transmitted in a physical control channel may be distributedbetween different control regions in a cascaded manner (e.g., between acommon control region or common search space and one or more UE-specificcontrol regions or UE-specific search spaces).

A carrier may be associated with a particular bandwidth of the radiofrequency spectrum, and in some examples the carrier bandwidth may bereferred to as a “system bandwidth” of the carrier or the wirelesscommunications system 100. For example, the carrier bandwidth may be oneof a number of predetermined bandwidths for carriers of a particularradio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 MHz). Insome examples, each served UE 115 may be configured for operating overportions or all of the carrier bandwidth. In other examples, some UEs115 may be configured for operation using a narrowband protocol typethat is associated with a predefined portion or range (e.g., set ofsubcarriers or RBs) within a carrier (e.g., “in-band” deployment of anarrowband protocol type).

In a system employing MCM techniques, a resource element may consist ofone symbol period (e.g., a duration of one modulation symbol) and onesubcarrier, where the symbol period and subcarrier spacing are inverselyrelated. The number of bits carried by each resource element may dependon the modulation scheme (e.g., the order of the modulation scheme).Thus, the more resource elements that a UE 115 receives and the higherthe order of the modulation scheme, the higher the data rate may be forthe UE 115. In MIMO systems, a wireless communications resource mayrefer to a combination of a radio frequency spectrum resource, a timeresource, and a spatial resource (e.g., spatial layers), and the use ofmultiple spatial layers may further increase the data rate forcommunications with a UE 115.

Devices of the wireless communications system 100 (e.g., base stations105 or UEs 115) may have a hardware configuration that supportscommunications over a particular carrier bandwidth, or may beconfigurable to support communications over one of a set of carrierbandwidths. In some examples, the wireless communications system 100 mayinclude base stations 105 and/or UEs that can support simultaneouscommunications via carriers associated with more than one differentcarrier bandwidth.

Wireless communications system 100 may support communication with a UE115 on multiple cells or carriers, a feature which may be referred to ascarrier aggregation (CA) or multi-carrier operation. A UE 115 may beconfigured with multiple downlink CCs and one or more uplink CCsaccording to a carrier aggregation configuration. Carrier aggregationmay be used with both FDD and TDD component carriers.

In some cases, wireless communications system 100 may utilize enhancedcomponent carriers (eCCs). An eCC may be characterized by one or morefeatures including wider carrier or frequency channel bandwidth, shortersymbol duration, shorter TTI duration, or modified control channelconfiguration. In some cases, an eCC may be associated with a carrieraggregation configuration or a dual connectivity configuration (e.g.,when multiple serving cells have a suboptimal or non-ideal backhaullink). An eCC may also be configured for use in unlicensed spectrum orshared spectrum (e.g., where more than one operator is allowed to usethe spectrum). An eCC characterized by wide carrier bandwidth mayinclude one or more segments that may be utilized by UEs 115 that arenot capable of monitoring the whole carrier bandwidth or are otherwiseconfigured to use a limited carrier bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than otherCCs, which may include use of a reduced symbol duration as compared withsymbol durations of the other CCs. A shorter symbol duration may beassociated with increased spacing between adjacent subcarriers. Adevice, such as a UE 115 or base station 105, utilizing eCCs maytransmit wideband signals (e.g., according to frequency channel orcarrier bandwidths of 20, 40, 60, 80 MHz, etc.) at reduced symboldurations (e.g., 16.67 microseconds). A TTI in eCC may consist of one ormultiple symbol periods. In some cases, the TTI duration (that is, thenumber of symbol periods in a TTI) may be variable.

Wireless communications systems 100 such as an NR system may utilize anycombination of licensed, shared, and unlicensed spectrum bands, amongothers. The flexibility of eCC symbol duration and subcarrier spacingmay allow for the use of eCC across multiple spectrums. In someexamples, NR shared spectrum may increase spectrum utilization andspectral efficiency, specifically through dynamic vertical (e.g., acrossfrequency) and horizontal (e.g., across time) sharing of resources.

In some wireless communications systems 100, base stations 105 and UEs115 may implement polar codes to encode and decode transmissions. Insome cases, a transmitting device (e.g., a base station 105 or a UE 115)may select a payload for transmission. The size of the payload may beconfigurable, for example, from a list of possible payload sizes orbased on the length of the codeword. In some cases, a receiving devicemonitoring for a codeword may monitor for any of the possible payloadsizes or codeword lengths. These decoding attempts, where the decoderdoes not know the codeword or payload sizes, may be referred to as blinddecoding.

To improve the success of blind decoding processes, the transmittingdevice may encode the codeword using one or more techniques to indicatethe payload size. The transmitting device may determine a set ofinformation bits for encoding, where the information bits may includethe payload bits and parity bits generated based on the payload bits.These information bits may be organized into a bit vector. Thetransmitting device may modify the bit vector based on the size of thepayload (e.g., the number of payload bits). In a first technique, thetransmitting device may determine a masking vector corresponding to thepayload size (e.g., from a table in memory or based on an equation). Thedevice may mask or scramble one or more bits of the bit vector using themasking vector. In a second technique, the device may position at leasta portion of the parity bits in the bit vector at lower bit indices thanthe payload bits. In a third technique, the device may ensure that thefirst bit index of the bit vector contains a bit value different thanthat of a default frozen bit value (e.g., if the frozen bits have valuesof 0, the first bit index will have a value of 1). For example, thedevice may insert an additional bit at the first bit index of the bitvector, or may arrange the payload bits so that the first bit will be a1 bit. In some cases, the bit vector described above may be referred toas an information bit vector and may be a portion of a larger bit vectorthat contains one or more frozen bits preceding the information bitvector. The transmitting device may assign the bits of the bit vector tocorresponding bit channels, and may generate a codeword using theassigned bit channels and a polar code. The device may transmit thisgenerated codeword to a receiving device (e.g., a base station 105 or aUE 115).

The receiving device may decode the codeword using a blind decodingprocess. For example, the receiving device may decode the receivedsignal using one or more hypotheses for the payload size. For each ofthe techniques described above, the decoding process may fail if thereceiving device assumes an incorrect payload size hypothesis. Forexample, in the first two techniques, a parity check or CRC may fail ifthe codeword is decoded using an incorrect masking vector or anincorrect starting position for the CRC. In the third technique, thereceiving device may determine the position of the first information bitwithin the bit vector, as this first information bit will be the firstbit with a value different than the default frozen bit value. Using oneor more of these techniques, the receiving device may successfullydecode codewords of different payload sizes.

FIG. 2 illustrates an example of a device 200 that supports polar codingtechniques for blind detection of different payload sizes in accordancewith aspects of the present disclosure. The device 200 may be includedin any device within a wireless communications system 100 that performsan encoding or decoding process (e.g., using an error-correcting code,such as a polar code). For example, device 200 may be included in a UE115 or a base station 105 as described with reference to FIG. 1.

As shown, device 200 includes a memory 205, an encoder/decoder 210, anda transmitter/receiver 215. First bus 220 may connect memory 205 toencoder/decoder 210 and second bus 225 may connect encoder/decoder 210to transmitter/receiver 215. In some instances, device 200 may have datastored in memory 205 to be transmitted to another device, such as a UE115 or base station 105. To initiate the transmission process, device200 may retrieve from memory 205 the data for transmission. The data mayinclude a number of payload bits, ‘A,’ which may be 1s or 0s, providedfrom memory 205 to encoder/decoder 210 via first bus 220. In some cases,these payload bits may be combined with a number of parity bits, ‘L,’ toform a total set of information bits, ‘A+L.’ The number of informationbits may be represented as a value ‘K,’ as shown. The encoder/decoder210 may encode the information bits and output a codeword having alength ‘N,’ which may be different than or the same as K. The bits thatare not allocated as information bits (i.e., N−K bits) may be assignedas frozen bits. In some cases, the information bits may be assigned tothe K most reliable bit channels, and the frozen bits may be assigned tothe remaining bit channels. Frozen bits may be bits of a default value(e.g., 0 or 1 or some other value) known to both the encoder and decoder(i.e., the encoder encoding information bits at a transmitter and thedecoder decoding the codeword received at a receiver). Further, from thereceiving device perspective, device 200 may receive encoded data viareceiver 215, and may decode the encoded data using decoder 210 toobtain the transmitted data.

In some wireless systems, decoder 210 may be an example of a successivecancellation (SC) or a successive cancellation list (SCL) decoder. A UE115 or base station 105 may receive a transmission including a codewordat receiver 215, and may pass the transmission to the SCL decoder (e.g.,decoder 210). The SCL decoder may determine input logarithmic-likelihoodratios (LLRs) for the bit channels of the received codeword. Duringdecoding, the SCL decoder may determine decoded LLRs based on theseinput LLRs, where the decoded LLRs correspond to each bit channel of thepolar code. These decoded LLRs may be referred to as bit metrics. Insome cases, if the LLR is zero or a positive value, the SCL decoder maydetermine the corresponding bit is a 0 bit and a negative LLR maycorrespond to a 1 bit. The SCL decoder may use the bit metrics todetermine the decoded bit values.

The SCL decoder may employ multiple concurrent SC decoding processes.Each SC decoding process may decode the codeword sequentially (e.g., inorder of the bit channel indices). Due to the combination of multiple SCdecoding processes, the SCL decoder may calculate multiple decoding pathcandidates. For example, an SCL decoder of list size ‘L’ (i.e., the SCLdecoder has L SC decoding processes) may calculate L decoding pathcandidates, and may calculate a corresponding reliability metric (e.g.,a path metric) for each decoding path candidate. The path metric mayrepresent a reliability of a decoding path candidate or a probabilitythat the corresponding decoding path candidate is the correct set ofdecoded bits. The path metric may be based on the determined bit metricsand the bit values selected at each bit channel. The SCL decoder mayhave a number of levels equal to the number of bit channels in thereceived codeword. At each level, each decoding path candidate mayselect either a 0 bit or a 1 bit based on a path metric of the 0 bit andthe 1 bit. The SCL decoder may select a decoding path candidate based onthe path metrics and may output the bits corresponding to the selecteddecoding path as the decoded sets of bits. For example, the SCL decodermay select the decoding paths with the highest path metrics.

If an SCL decoder determines that the first number of bits are allfrozen bits, the SCL decoder may determine that the correct decodingpath for the first number of bits must be the default frozen bit values(e.g., if the default frozen bit value is 0, the correct decoding pathfor the first number of bits must be all 0's). Once the SCL decoderreaches the first information bit, the SCL decoder may begin performingoperations to decode the rest of the bits of the codeword, as the SCLdecoder may not be able to determine the correct decoding path from thefirst information bit onwards (e.g., because the first information bitmay be a 0 or a 1) without subsequent decoding operations. However, theSCL decoder may still determine bit metrics for the bit channelscontaining frozen bits and may use these bit metrics when calculatingpath metrics for the decoding path candidates. For example, the SCLdecoder may update the path metric for the decoding candidates afterevery bit, regardless of bit type (e.g., after each frozen bit orinformation bit).

To decode a polar coded codeword, device 200 may perform blind decoding.For example, receiver 215 may be configured with a set of candidatehypotheses for the codeword, where each candidate may correspond to aset of N:K or N:A hypotheses. Receiver 215 may identify one or morecandidate codewords received over a channel, and may attempt to processeach candidate codeword using different N:K or N:A assumptions. In somecases, decoder 210 may decode the signal received by receiver 215 toobtain a set of information bits, which may include parity bits andpayload bits for a data payload. Decoder 210 may perform a CRC or paritycheck on the payload bits for the data payload using the parity bits,and may determine that the data payload represents a successfullydecoded codeword intended for device 200 if the parity check passes.

However, in some cases, the decoding operation may fail because thecodeword has experienced excessive corruption (e.g., the channel has avery low signal to noise ratio (SNR)), there is no transmitted codewordfor the candidate hypothesis (e.g., the codeword represents randomnoise), the transmitted codeword is intended for a different device, orthe candidate hypothesis may be incorrect (e.g., the N:K or 1V:Aassumptions are incorrect). In these cases, decoder 210 may detect adecoding failure and attempt decoding using a different candidatecodeword.

Further, in some cases of blind decoding, the decoder 210 may not beable to distinguish between certain codewords. In a blind decodingprocess, for example, the decoder 210 may identically process frozenbits and information bits that have the same bit value as the frozenbits. For example, if the decoder 210 has not identified the number ofinformation bits, K, within the codeword, the decoder 210 may not beable to determine whether an LLR indicating the default frozen bit value(e.g., a 0) corresponds to a frozen bit or an information bit thathappens to have the same value. Accordingly, if an encoder 210 mapsinformation bits with frozen bit values (e.g., information bits withvalues of 0) to the least reliable information bit channels, a decoder210 receiving the codeword may not be able to determine whether thosebit channels are the least reliable information bit channels or the mostreliable frozen bit channels. In such cases, the decoder 210 may not beable to determine the correct number of information bits, K, or payloadbits, A, encoded in the codeword.

In some cases, parity bits may not indicate whether bits having the samevalues as frozen bits are information bits or frozen bits. For example,if the parity bits are CRC bits, the encoder 210 may determine the bitvalues for the parity bits based on the payload bits. However, theparity bits may be determined by the encoder 210 in order of increasingpayload reliability, and may not be updated in view of frozen bitvalues. For example, the encoder 210 may generate a default parity bitstring corresponding to a portion of—or the entire—set of payload bits.The encoder 210 may update the default parity bit string for eachpayload bit with a bit value of 1, and may not update the parity bitstring for payload bits with a bit value of 0 (e.g., if the frozen bitshave bit values of 0). In this way, when a decoder 210 decodes thepayload bits, the decoder 210 may perform the same process to determinea parity bit string, and may compare the determined parity bit string tothe actual received parity bit string to determine if the payload bitsare decoded correctly (e.g., if the parity bit strings match). However,as the encoder 210 does not update the default parity bit string forleading information bits with values of 0, the parity bit strings may beidentical for a payload with leading 0 bits and for a payload ofotherwise the same bits but without the leading 0 bits.

In one specific example of information bit index mapping, an encoder 210may, in a first case, encode 78 information bits (e.g., 54 payload bitsand 24 CRC bits) within a 108 bit codeword. The encoder 210 may selectthe 78 most reliable bit channels of the 108 total bit channels for thepolar code and may map the 78 information bits to these 78 selected bitchannels. In such a case, the most reliable bit channel of the 108 totalbit channels may be bit channel 107 and bit channel 14may be the leastreliable of the 78 selected information bit channels. The encoder 210may generate a bit vector containing the payload bits and the CRC bits(e.g., with the CRC bits at the end of the bit vector, or with the CRCbits interleaved throughout the bit vector, etc.) and may assign thebits of the bit vector to the information bit channels. For example, theencoder 210 may assign the information bit in the first bit index of thebit vector to the least reliable information bit channel (e.g., bitchannel 14). If this first information bit is a 0 bit (e.g., the frozenbit value), the encoder 210 may set bit channel 14 to a 0 bit. However,if in another case the encoder 210 encodes 77 information bits (e.g., 54payload bits and 24 CRC bits) within a 108 bit codeword, bit channel 14may be the most reliable frozen bit channel. In either case, the encoder210 may assign a 0 bit to bit channel 14. Hence, if the remaining 77bits of the bit vectors are the same in the two cases described above,the encoder 210 may output identical codewords for the two cases,despite the first codeword including 78 information bits and the secondcodeword including 77 information bits. Accordingly, a decoder 210 blinddecoding these codewords may not be able to determine whether thecodeword includes 77 or 78 information bits.

To facilitate differentiation between codewords like the two describedabove, the encoder 210 may include an indication of the payload size(e.g., the number of payload bits) or the number of information bits inthe codeword. For example, the encoder 210 may modify the bit vector(e.g., an order of the bit vector or content of the bit vector) based onthe payload size. In a first such technique, the encoder 210 may performa masking operation on the bit vector using a masking vector, where theselected masking vector is based on the payload size. In a second suchtechnique, the encoder 210 may arrange the payload bits and parity bitsin the bit vector such that one or more of the parity bits arepositioned first in the bit vector. If at least one of the front-loadedparity bits has a different bit value than the default frozen bit value(e.g., if at least one of these parity bits is a 1), a decoder 210 maybe able to determine the correct number of payload or information bitsin the codeword. In a third such technique, the encoder 210 may modifythe contents of the bit vector to indicate the start of the informationbits. As one example of such a third technique, the encoder 210 mayinsert a 1 bit at the front of the bit vector to indicate the leastreliable of the information bit channels. As another example of such athird technique, the encoder 210 may arrange the payload bits such thata first bit in the bit vector is a 1 bit. Any of these techniques mayprovide an indication of the least reliable information bit channel to adecoder 210 decoding the codeword. Based on the index of this indicatedchannel, the codeword size, and the configured number of parity bits(e.g., the encoder 210 and decoder 210 may include an indication of theconfigured number of parity or CRC bits for a codeword), the decoder 210may determine the number of payload bits in a blind decoding processeven in problematic cases such as those described above, which may aidthe decoder 210 in correctly determining the transmitted data payloadwithout any negative impact to the block error ratio (BLER).

FIG. 3 illustrates an example of a polar encoding process 300 thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure. Thepolar encoding process 300 may be performed by an encoder 210 asdescribed above, for example, with reference to FIG. 2. The encoder 210may be a component of a wireless device, such as a base station 105 or aUE 115, as described with reference to FIG. 1. The polar encodingprocess 300 may include bit vector manipulation to indicate a payloadsize to aid in blind decoding at a receiving device.

At 305, an encoder may receive a number of payload bits, A,corresponding to a data payload. For example, the device may sendinformation from memory, represented by the payload bits, to theencoder. This information may be encoded into a codeword and transmittedto a receiving device.

At 310, the encoder may generate and attach an L-bit CRC to the Apayload bits to form a set of K information bits. In some cases, theencoder may use other forms of parity bits instead of or in addition tothe CRC bits. To determine the CRC bits, the encoder may perform a CRCoperation on the payload bits. This CRC operation may be known to areceiving device as well, so that a receiving device decoding thecodeword may use the same CRC operation to determine whether thedecoding process was successful. In some CRC operations, the generatedCRC bits may not be affected by leading zeros in the payload.

At 315, the encoder may optionally pass the K information bits (e.g.,including the A payload bits and the L CRC bits) to an interleaver. At320, the interleaver may interleave portions of the CRC bits throughoutthe payload bits (e.g., to support early termination at a decoder). Forexample, for a 24-bit CRC, a 6-bit CRC may be positioned approximately aquarter of the way through the information bits, another 6-bit CRC maybe positioned halfway through the information bits, and the remaining12-bit CRC may be positioned at the end of the information bits. At 325,the interleaver may pass the interleaved K information bits to a polarencoding process 330.

In addition to the K information bits, the polar encoding process 330may receive K bit indices corresponding to bit channels for theinformation bits. For example, at 335, the encoder may receive a numberof bit indices, N, corresponding to the length of the codeword. At 340,the encoder may determine the information bit locations based on thenumber of bit indices, N, and the number of information bits to encodewithin the codeword, K. For example, the encoder may store a table inmemory indicating the K most reliable bit channels within N total bitchannels for multiple N, K pairs. In other cases, the encoder mayinclude a function that determines the most reliable bit channels for apolar code based on inputting the N and K values. At 345, the encodermay pass the K bit indices corresponding to these K most reliable bitchannels to the polar encoding process 330.

At 350, the encoder may set each bit of an N-length bit vector to frozenbit values (e.g., 0). Alternatively, the encoder may set the first N−Kbits of the bit vector to the frozen bit value. In either case, theencoder may fill in the bit vector with the information bits. Forexample, starting with the bit index following the N−K frozen bits, theencoder may insert the first bit of the information bits into the bitvector, and may continue inserting information bits into the bit vectoruntil the last information bit is inserted into the last bit index ofthe N-length bit vector.

To support blind detection of different payload sizes, the encoder maymodify this bit vector using one or more techniques. For example, theencoder may scramble the A payload bits, the L parity bits, the N−Kfrozen bits, or any combination of these bits using a masking value orvector corresponding to the payload size, A, or the number ofinformation bits, K (e.g., where the number of information bits isimplicitly based on the payload size and a configured number of CRCbits, L). In another example, the encoder (e.g., at the interleaver orduring the polar encoding process 330) may position one or more CRC bitsafter the frozen bits in the bit vector, where at least one of the CRCbits has a bit value different than the frozen bits (e.g., a bit valueof 1 if the frozen bits have a bit value of 0). In yet other examples,the encoder may either insert an additional bit having a bit valuedifferent than the frozen bits (e.g., a bit value of 1 if the frozenbits have a bit value of 0) after the frozen bits or may arrange thepayload bits such that the first bit after the frozen bits has a bitvalue different than the frozen bits (e.g., a bit value of 1 if thefrozen bits have a bit value of 0). With any of these techniques, aloneor in combination, the encoder may modify the bit vector such that thebits within the bit vector or the order of the bits within the bitvector indicates the payload size or the number of information bits.

At 355, the encoder may send this modified N-bit bit vector to a polarencoding operation, where the encoder may perform a polar transformation360 on the N-bit vector. For example, the polar transformation 360 mayassign the N bits of the bit vector to the N bit channels of the polarcode, where the K information bits are assigned to the most reliablechannels according to the K bit indices received at 345. Based on thesebit channel assignments, the encoder may transform the bits using apolarizing transform (e.g., implementing F and G operations) todetermine the bits to transmit within a codeword. This polarizingtransform may result in the different reliabilities for the bitchannels.

At 365, the encoder may send the N-bit codeword resulting from the polarencoding process 330 to a rate matching process 370. The rate matchingprocess 370 may modify the codeword for transmission at a specificcoding rate. Following the rate matching process 370, the codeword maybe sent to a transmitter at 375. The transmitter may transmit thecodeword over a channel to a receiving device. In some cases (e.g., ifthe receiving device has not previously received a codeword from thetransmitting device, or if the transmitting device modified a payloadsize for transmission), the receiving device may use N, K or N, Ahypotheses in a blind decoding process to determine the size of thepayload transmitted using the codeword. Based on the modification to thebit vector (e.g., an order of the bit vector or content of the bitvector), the receiving device may correctly determine the payload sizeof the received codeword, regardless of leading zero bits in thepayload.

FIGS. 4A, 4B, and 4C illustrate examples of payload size indications 400that support polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure. Thepayload size indications 400 may be incorporated into bit vectors forblind detection of different payload sizes. These payload sizeindications 400 may facilitate determination by a decoder of a payloadsize based on a single polar decoding process.

FIG. 4A illustrates an example of a payload size indication 400-a thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure. Thepayload size indication 400-a includes information bits 415-a, which mayinclude both payload bits 405-a and parity bits (e.g., CRC bits 410-a)associated with the payload bits 405-a. The information bits 415-a maybe combined with frozen bits 420-a to form a bit vector. An encoder(e.g., as described with respect to FIGS. 2 and 3) may modify this bitvector based on a payload size in order to indicate the payload size.

For example, the encoder may include a mapping of payload sizes tomasking vectors or values (e.g., referred to as a payload size mask430). In some cases, the encoder may store a table in memory, where eachconfigurable payload size indicates to a corresponding payload size mask430. In some examples, this mapping may be further based on the codewordsize, the number of CRC bits 410-a, or some combination of these. Theencoder may determine the payload size mask 430 based on the payloadsize, and may perform a masking or scrambling operation 425 on the bitvector using the determined payload size mask 430. For example, themasking or scrambling operation 425 may be an example of an exclusive or(XOR) operation. Depending on the size of the payload size mask 430,this masking or scrambling operation 425 may be performed as a bit-wiseoperation, or may be performed on portions of the bit vector. The sizeof the payload size mask 430 may depend on the number of possiblepayload sizes (e.g., if the encoder supports two possible payload sizeconfigurations, the encoder may incorporate a one bit payload size mask430, where a mask with a value of 0 indicates one payload size and amask with a value of 1 indicates the other payload size). Additionallyor alternatively, the size of the payload size mask 430 may depend onthe number of bits to scramble or mask (e.g., in order for thevector-to-vector masking or scrambling operation 425 to be performed).In some cases, the encoder may perform the masking or scramblingoperation 425 on one or more of the frozen bits 420-a, the payload bits405-a, the CRC bits 410-a, or any combination of these bits. The encodermay use this masked or scrambled bit vector to generate a codeword usinga polar code.

A receiving device receiving the codeword (e.g., as a candidate codewordin a blind detection process) may send the codeword to a polar decoderfor blind decoding. The polar decoder may determine decoded LLRs basedon the received LLRs for the codeword, and may make soft or hard bitdecisions based on these decoded LLRs. Each of these decoded LLRs maycorrespond to a bit of the modified bit vector. To determine the decodedLLRs, the decoder may assume an N, K hypothesis. The decoder may use theK value of the hypothesis to determine an assumed payload size based ona configured number of CRC bits 410-a. The decoder may contain the samemapping of payload sizes to payload size masks 430 in memory. Using thismapping, the decoder may select the payload size mask 430 correspondingto the assumed payload size, and may de-mask or de-scramble the hard bitdecisions for the decoded LLRs using the selected payload size mask 430.If the de-masked or de-scrambled bits pass the CRC (e.g., based on thepayload bits 405-a and the CRC bits 410-a), the decoder may determinethat the correct payload size was assumed. Using these techniques, thedecoder may determine the correct data payload (e.g., payload bits405-a) even if the payload bits 405-a include leading bits having thesame value as frozen bits (e.g., leading 0 bits).

FIG. 4B illustrates an example of a payload size indication 400-b thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure. Thepayload size indication 400-b includes information bits 415-b, which mayinclude both payload bits 405-b and CRC bits 410-b associated with thepayload bits 405-b (e.g., determined based on the payload bits 405-b).The information bits 415-b may be combined with frozen bits 420-b toform a bit vector. An encoder (e.g., as described with respect to FIGS.2 and 3) may modify the interleaving of information bits 415-b withinthis bit vector to indicate the payload size. While the following isdescribed with respect to CRC bits, it should be understood that theoperations apply to any type of parity or check bits.

To indicate the size of the payload, the encoder may position one ormore CRC bits 410-b ahead of the payload bits 405-b in the bit vector.For example, the CRC bits 410-b may be placed at lower bit indices thanthe payload bits 405-b. In some cases, the encoder may interleave CRCbits 410-b throughout the payload bits 405-b, but may position one ormore CRC bits at the bit indices directly following the frozen bits420-b in the bit vector, where at least one of these CRC bits has adifferent bit value than the default frozen bit value. This at least oneCRC bit—and any other contiguous CRC bits—may be referred to asfront-loaded CRC bits. The encoder may use this arrangement of bits inthe bit vector to encode the codeword for transmission. For example, theencoder may map the reordered bit vector to bit channels of the polarcode, where the bits of the bit vector are mapped in increasing indexorder to bit channels of the polar code in ascending reliability order.

A decoder decoding the codeword at a receiving device may perform one ormore CRCs on the decoded bits based on one or more hypotheses for theposition of the front-loaded CRC bits. For example, the encoder anddecoder may be configured with a set number of CRC bits forfront-loading in the bit vector. Based on the received LLRs, the setnumber of front-loaded CRC bits, the possible payload sizeconfigurations, or any combination of these parameters, the decoder mayperform CRCs using different hypotheses for the positioning of thefront-loaded CRC bits. If a hypothesis passes the CRC, the decoder maydetermine that the assumed front-loaded CRC position is correct. In suchcases, based on the positioning of the front-loaded CRC, the decoder maydetermine the number of information bits 415-b encoded in the codewordand, accordingly, the payload size. In this way, even if the payloadbits 405-b or the CRC bits 410-a include leading 0 bits, the CRC willonly pass if the correct payload size is assumed at the decoder.

FIG. 4C illustrates an example of a payload size indication 400-c thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure. Thepayload size indication 400-c includes information bits 415-c, which mayinclude both payload bits 405-c and CRC bits 410-c associated with thepayload bits 405-c. An encoder (e.g., as described with respect to FIGS.2 and 3) may modify the payload bits 405-c to indicate the payload size.The encoder may combine these modified payload bits 435 with the CRCbits 410-c to form the information bits 415-c, and may further combinethe information bits 415-c with the frozen bits 420-c to form a bitvector for encoding.

In a first example, the encoder may append a single bit to the front ofthe payload bits 405-c to form the modified payload bits 435. Thissingle bit may have a bit value different than that of the frozen bits.For example, if the default frozen bit value is 0, the encoder mayinsert a bit of bit value 1. This inserted bit may be positioned in thebit index directly following the frozen bits 420-c within the bitvector.

In some cases, the bit is inserted by changing (e.g., switching from 0to 1) the value of the frozen bit in the highest bit index within thebit vector. In other cases, the encoder may select a number ofinformation bits 415-c for encoding based on the additional bit. Forexample, the number of information bits 415-c may equal the sum of thenumber of payload bits 405-c and the number of CRC bits 410-c plus one.In certain examples, the encoder may include this additional bit toindicate different types of messages. For example, depending on theinformation corresponding to the data payload, the encoder may determinewhether or not to insert the bit indicating the start of the informationbits 415-c within the bit vector.

In a second example, the encoder may arrange the payload bits 405-c sothat a bit with a particular value (e.g., a value of 1) is in this firstbit position. For example, the encoder may arrange the payload bits405-a for a downlink control information (DCI) format 1A message suchthat the bit indicating the “Flag for format 0/1A differentiation” fieldis positioned first in the payload. As this bit has a bit value of 1 forall DCI format 1A messages, the encoder may ensure that the first bit inthe modified payload bits 435 is a 1. The encoder may then position themodified payload bits 435 in the bit vector following the frozen bits420-c, so that the first information bit 415-c positioned in the bitindex following the frozen bits 420-c will have a different bit valuethan the frozen bits 420-c. This bit may mark the start of theinformation bits 415-c within the bit vector and, accordingly, mayindicate the payload size.

A decoder decoding the codeword at a receiving device may be configuredto determine the start of the information bits 415-c within a codewordbased on a decoded LLR indicating a value different than that of afrozen bit (e.g., for a default frozen bit value of 0, the decoder maydetermine the information bits 415-c start when identifying an LLRcorresponding to a 1). Based on the identified start of the informationbits within the bit vector, the decoder may correctly determine the sizeof the payload.

FIG. 5 illustrates an example of a process flow 500 that supports polarcoding techniques for blind detection of different payload sizes inaccordance with aspects of the present disclosure. The process flow 500may include base station 105-a and UE 115-a, which may be examples ofthe corresponding devices described with reference to FIG. 1. Asillustrated, base station 105-a may perform encoding processes and UE115-a may perform decoding processes on a codeword transmitted in thedownlink. However, it is to be understood that UE 115-a may also performthe encoding processes, and base station 105-a the decoding processes.Additionally or alternatively, the polar coding processes described maybe implemented in device-to-device (D2D) communications or backhaulcommunications between base stations 105 or UEs 115, or other devices.

At 505, the encoding device (e.g., base station 105-a) may identify apayload for transmission. The payload may include an ordered set ofpayload bits, which may or may not include one or more leading bits withbit values equal to a frozen bit value (e.g., leading bits with bitvalues of 0 if the default frozen bit value for polar codes is 0).

At 510, base station 105-a may determine a bit vector based on the sizeof the payload. The bit vector may include the set of payload bits, andin some cases may include a set of parity bits based on the payloadbits, a set of frozen bits, or some combination of these bits. The bitsin the bit vector or an order of the bits in the bit vector may be basedon the payload size. For example, base station 105-a may scramble thebits in the bit vector using a masking vector, where the masking vectoris determined based on the payload size. In another example, basestation 105-a may position the set of parity bits in a lowest bit indexof the bit vector, where the payload bits are positioned in higher bitindices of the bit vector. In some cases, the “lowest” bit index mayrefer to the lowest bit index amongst information bit indices, where thefrozen bits may be positioned in bit indices lower than the “lowest” bitindex. In yet another example, base station 105-a may append an initialbit to the bit vector, where the initial bit has a bit value differentthan that of the default frozen bit value. Alternatively, base station105-a may arrange the payload bits or the parity bits such that aninitial bit of the bit vector has a bit value different than that of thedefault frozen bit value. Similar to above, the “initial” bit maycorrespond to the initial information bit, where the frozen bits mayprecede this “initial” bit within the bit vector.

At 515, base station 105-a may generate a codeword using a polar codeand the bit vector. For example, base station 105-a may assign the bitsof the bit vector to bit channels of the polar code. At 520, basestation 105-a may transmit the generated codeword. A receiving device(e.g., UE 115-a) may receive the codeword as a candidate codeword, andmay attempt to decode the candidate codeword.

At 525, UE 115-a may perform a blind decoding process on the receivedcodeword. For example, at 530, UE 115-a may determine a payload size forthe codeword. At 535, UE 115-a may decode the codeword based on thedetermined payload size to obtain a bit vector. In some cases,determining the payload size and decoding the codeword may occur basedon UE 115-a assuming one or more hypothesis payload sizes, andperforming checks to determine if a hypothesis payload size results in acorrectly decoded codeword. For example, UE 115-a may de-scramble thehard bit decisions for the LLRs of the codeword using a masking vectorcorresponding to the hypothesis payload size. If the de-scrambled bitspass a CRC (e.g., the de-scrambling is successful), UE 115-a maydetermine that the hypothesis payload size is correct. In anotherexample, UE 115-a may perform one or more CRCs or parity checks based onassumed positions of CRC or parity bits within the bit vector, and maydetermine the correct payload size based on the positioning that resultsin a successful CRC or parity check. In yet other examples, UE 115-a mayidentify the least reliable bit channel with an LLR indicating a bitwith a bit value different than that of the default frozen bit value,and may determine that this bit channel is the first information bitchannel. Based on this determination, UE 115-a may determine the payloadsize. At 540, UE 115-a may parse the obtained bit vector based on thedetermined payload size to identify the payload bits encoded within thecodeword.

FIG. 6 shows a block diagram 600 of a wireless device 605 that supportspolar coding techniques for blind detection of different payload sizesin accordance with aspects of the present disclosure. Wireless device605 may be an example of aspects of a base station 105 or a UE 115,including an encoder, as described above with reference to FIGS. 1 and2. Wireless device 605 may include receiver 610, encoder polar codingmodule 615, and transmitter 620. Wireless device 605 may also include aprocessor. Each of these components may be in communication with oneanother (e.g., via one or more buses).

Receiver 610 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to polar codingtechniques for blind detection of different payload sizes, etc.).Information may be passed on to other components of the device. Thereceiver 610 may be an example of aspects of the transceiver 935described with reference to FIG. 9. The receiver 610 may utilize asingle antenna or a set of antennas.

Encoder polar coding module 615 may be an example of aspects of theencoder polar coding module 915 described with reference to FIG. 9.Encoder polar coding module 615 and/or at least some of its varioussub-components may be implemented in hardware, software executed by aprocessor, firmware, or any combination thereof. If implemented insoftware executed by a processor, the functions of the encoder polarcoding module 615 and/or at least some of its various sub-components maybe executed by a general-purpose processor, a digital signal processor(DSP), an application-specific integrated circuit (ASIC), anfield-programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described in thepresent disclosure. The encoder polar coding module 615 and/or at leastsome of its various sub-components may be physically located at variouspositions, including being distributed such that portions of functionsare implemented at different physical locations by one or more physicaldevices. In some examples, encoder polar coding module 615 and/or atleast some of its various sub-components may be a separate and distinctcomponent in accordance with aspects of the present disclosure. In otherexamples, encoder polar coding module 615 and/or at least some of itsvarious sub-components may be combined with one or more other hardwarecomponents, including but not limited to an I/O component, atransceiver, a network server, another computing device, one or moreother components described in the present disclosure, or a combinationthereof in accordance with aspects of the present disclosure.

Encoder polar coding module 615 may identify a set of payload bits of apayload for encoding, determine a bit vector including the set ofpayload bits, where at least one bit or a bit order of the bit vector isbased on a size of the payload, generate a polar-encoded codeword usingthe bit vector, and transmit the codeword.

Transmitter 620 may transmit signals generated by other components ofthe device. In some examples, the transmitter 620 may be collocated witha receiver 610 in a transceiver module. For example, the transmitter 620may be an example of aspects of the transceiver 935 described withreference to FIG. 9. The transmitter 620 may utilize a single antenna ora set of antennas.

FIG. 7 shows a block diagram 700 of a wireless device 705 that supportspolar coding techniques for blind detection of different payload sizesin accordance with aspects of the present disclosure. Wireless device705 may be an example of aspects of a wireless device 605, a basestation 105, or a UE 115 (e.g., including an encoder) as described abovewith reference to FIGS. 1, 2, and 6. Wireless device 705 may includereceiver 710, encoder polar coding module 715, and transmitter 720.Wireless device 705 may also include a processor. Each of thesecomponents may be in communication with one another (e.g., via one ormore buses).

Receiver 710 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to polar codingtechniques for blind detection of different payload sizes, etc.).Information may be passed on to other components of the device. Thereceiver 710 may be an example of aspects of the transceiver 935described with reference to FIG. 9. The receiver 710 may utilize asingle antenna or a set of antennas.

Encoder polar coding module 715 may be an example of aspects of theencoder polar coding module 915 described with reference to FIG. 9.Encoder polar coding module 715 may also include payload component 725,bit vector component 730, polar encoding component 735, and transmissioncomponent 740.

Payload component 725 may identify a set of payload bits of a payloadfor encoding. Bit vector component 730 may determine a bit vectorincluding the set of payload bits, where at least one bit or a bit orderof the bit vector is based on a size of the payload. In some cases, thebit vector includes the set of payload bits and a set of parity bitsassociated with the set of payload bits. Polar encoding component 735may generate a polar-encoded codeword based on the bit vector.Transmission component 740 may transmit the codeword.

Transmitter 720 may transmit signals generated by other components ofthe device. In some examples, the transmitter 720 may be collocated witha receiver 710 in a transceiver module. For example, the transmitter 720may be an example of aspects of the transceiver 935 described withreference to FIG. 9. The transmitter 720 may utilize a single antenna ora set of antennas.

FIG. 8 shows a block diagram 800 of an encoder polar coding module 815that supports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure. Theencoder polar coding module 815 may be an example of aspects of anencoder polar coding module 615, an encoder polar coding module 715, oran encoder polar coding module 915 described with reference to FIGS. 6,7, and 9. The encoder polar coding module 815 may include payloadcomponent 820, bit vector component 825, polar encoding component 830,transmission component 835, masking component 840, parity bitfront-loading component 845, parity bit generator 850, indicator bitcomponent 855, and bit vector arranging component 860. Each of thesemodules may communicate, directly or indirectly, with one another (e.g.,via one or more buses).

Payload component 820 may identify a set of payload bits of a payloadfor encoding. Bit vector component 825 may determine a bit vectorincluding the set of payload bits, where at least one bit or a bit orderof the bit vector is based on a size of the payload. In some cases, thebit vector includes the set of payload bits and a set of parity bitsassociated with the set of payload bits.

Polar encoding component 830 may generate a polar-encoded codeword basedon the bit vector. Transmission component 835 may transmit the codeword.

Masking component 840 may determine a masking vector corresponding tothe size of the payload, and may scramble the set of payload bits, a setof parity bits associated with the set of payload bits, a set of frozenbits, or a combination thereof with the masking vector. In some cases,scrambling the set of payload bits, the set of parity bits, the set offrozen bits, or the combination thereof with the masking vector includesan XOR operation.

In some cases, the bit vector may include a set of parity bits. Paritybit front-loading component 845 may position at least one bit of the setof parity bits in a lowest index of the bit vector, where the set ofpayload bits are positioned in higher indices of the bit vector. In somecases, parity bit front-loading component 845 may assign the set ofpayload bits and the set of parity bits to a set of information bitchannels of a polar code, where the at least one bit of the set ofparity bits is assigned to a least reliable channel of the set ofinformation bit channels.

Parity bit generator 850 may apply a parity function to the set ofpayload bits to generate the set of parity bits. In some cases, the setof parity bits includes a set of CRC bits.

Indicator bit component 855 may append an initial bit to the bit vector,where the initial bit includes an opposite bit value to a default frozenbit value. In some cases, the initial bit indicates a message typeassociated with the payload.

Bit vector arranging component 860 may arrange the set of payload bits,a set of parity bits associated with the set of payload bits, a set offrozen bits, or a combination thereof so that an initial bit of the bitvector includes an opposite bit value to a default frozen bit value.

FIG. 9 shows a block diagram of a system 900 including a device 905 thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.Device 905 may be an example of or include the components of wirelessdevice 605, wireless device 705, a base station 105, a UE 115, or anencoder as described above, e.g., with reference to FIGS. 1, 2, 6, and7. Device 905 may include components for bi-directional voice and datacommunications including components for transmitting and receivingcommunications, including encoder polar coding module 915, processor920, memory 925, software 930, transceiver 935, and I/O controller 940.These components may be in electronic communication via one or morebuses (e.g., bus 910).

Processor 920 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a central processing unit (CPU), amicrocontroller, an ASIC, an FPGA, a programmable logic device, adiscrete gate or transistor logic component, a discrete hardwarecomponent, or any combination thereof). In some cases, processor 920 maybe configured to operate a memory array using a memory controller. Inother cases, a memory controller may be integrated into processor 920.Processor 920 may be configured to execute computer-readableinstructions stored in a memory to perform various functions (e.g.,functions or tasks supporting polar coding techniques for blinddetection of different payload sizes).

Memory 925 may include random access memory (RAM) and read only memory(ROM). The memory 925 may store computer-readable, computer-executablesoftware 930 including instructions that, when executed, cause theprocessor to perform various functions described herein. In some cases,the memory 925 may contain, among other things, a basic input/outputsystem (BIOS) which may control basic hardware or software operationsuch as the interaction with peripheral components or devices.

Software 930 may include code to implement aspects of the presentdisclosure, including code to support polar coding techniques for blinddetection of different payload sizes. Software 930 may be stored in anon-transitory computer-readable medium such as system memory or othermemory. In some cases, the software 930 may not be directly executableby the processor but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

Transceiver 935 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 935 may represent a wireless transceiver and may communicatebi-directionally with another wireless transceiver. The transceiver 935may also include a modem to modulate the packets and provide themodulated packets to the antennas for transmission, and to demodulatepackets received from the antennas.

I/O controller 940 may manage input and output signals for device 905.I/O controller 940 may also manage peripherals not integrated intodevice 905. In some cases, I/O controller 940 may represent a physicalconnection or port to an external peripheral. In some cases, I/Ocontroller 940 may utilize an operating system such as iOS®, ANDROID®,MS-DOS®, MS-WINDOWS®, OO/2®, UNIX®, LINUX®, or another known operatingsystem. In other cases, I/O controller 940 may represent or interactwith a modem, a keyboard, a mouse, a touchscreen, or a similar device.In some cases, I/O controller 940 may be implemented as part of aprocessor. In some cases, a user may interact with device 905 via I/Ocontroller 940 or via hardware components controlled by I/O controller940.

FIG. 10 shows a block diagram 1000 of a wireless device 1005 thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.Wireless device 1005 may be an example of aspects of a base station 105or a UE 115, including a decoder, as described above with reference toFIGS. 1 and 2. Wireless device 1005 may include receiver 1010, decoderpolar coding module 1015, and transmitter 1020. Wireless device 1005 mayalso include a processor. Each of these components may be incommunication with one another (e.g., via one or more buses).

Receiver 1010 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to polar codingtechniques for blind detection of different payload sizes, etc.).Information may be passed on to other components of the device. Thereceiver 1010 may be an example of aspects of the transceiver 1335described with reference to FIG. 13. The receiver 1010 may utilize asingle antenna or a set of antennas.

Decoder polar coding module 1015 may be an example of aspects of thedecoder polar coding module 1315 described with reference to FIG. 13.Decoder polar coding module 1015 and/or at least some of its varioussub-components may be implemented in hardware, software executed by aprocessor, firmware, or any combination thereof. If implemented insoftware executed by a processor, the functions of the decoder polarcoding module 1015 and/or at least some of its various sub-componentsmay be executed by a general-purpose processor, a DSP, an ASIC, an FPGAor other programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described in the present disclosure. The decoderpolar coding module 1015 and/or at least some of its varioussub-components may be physically located at various positions, includingbeing distributed such that portions of functions are implemented atdifferent physical locations by one or more physical devices. In someexamples, decoder polar coding module 1015 and/or at least some of itsvarious sub-components may be a separate and distinct component inaccordance with aspects of the present disclosure. In other examples,decoder polar coding module 1015 and/or at least some of its varioussub-components may be combined with one or more other hardwarecomponents, including but not limited to an I/O component, atransceiver, a network server, another computing device, one or moreother components described in the present disclosure, or a combinationthereof in accordance with aspects of the present disclosure.

Decoder polar coding module 1015 may receive a polar-encoded codeword,the polar-encoded codeword generated based on a bit vector including aset of payload bits of a payload, and perform a blind decoding processon the polar-encoded codeword. The blind decoding process may includedetermining a size of the payload based on at least one LLR associatedwith the bit vector, decoding the polar-encoded codeword to obtain thebit vector based on the determined size of the payload, and parsing thebit vector to obtain the set of payload bits based on the determinedsize of the payload.

Transmitter 1020 may transmit signals generated by other components ofthe device. In some examples, the transmitter 1020 may be collocatedwith a receiver 1010 in a transceiver module. For example, thetransmitter 1020 may be an example of aspects of the transceiver 1335described with reference to FIG. 13. The transmitter 1020 may utilize asingle antenna or a set of antennas.

FIG. 11 shows a block diagram 1100 of a wireless device 1105 thatsupports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.Wireless device 1105 may be an example of aspects of a wireless device1005, a base station 105, a UE 115, or a decoder as described withreference to FIGS. 1, 2, and 10. Wireless device 1105 may includereceiver 1110, decoder polar coding module 1115, and transmitter 1120.Wireless device 1105 may also include a processor. Each of thesecomponents may be in communication with one another (e.g., via one ormore buses).

Receiver 1110 may receive information such as packets, user data, orcontrol information associated with various information channels (e.g.,control channels, data channels, and information related to polar codingtechniques for blind detection of different payload sizes, etc.).Information may be passed on to other components of the device. Thereceiver 1110 may be an example of aspects of the transceiver 1335described with reference to FIG. 13. The receiver 1110 may utilize asingle antenna or a set of antennas.

Decoder polar coding module 1115 may be an example of aspects of thedecoder polar coding module 1315 described with reference to FIG. 13.Decoder polar coding module 1115 may also include reception component1125, polar decoding component 1130, payload size determinationcomponent 1135, and bit vector parser 1140.

Reception component 1125 may receive a codeword encoded using a polarcode, the codeword generated based on a bit vector including a set ofpayload bits of a payload.

Polar decoding component 1130 may perform a blind decoding process onthe codeword. For example, payload size determination component 1135 maydetermine a size of the payload based on at least one LLR associatedwith the bit vector. Polar decoding component 1130 may decode thecodeword to obtain the bit vector based on the determined size of thepayload. Bit vector parser 1140 may parse the bit vector to obtain theset of payload bits based on the determined size of the payload.

Transmitter 1120 may transmit signals generated by other components ofthe device. In some examples, the transmitter 1120 may be collocatedwith a receiver 1110 in a transceiver module. For example, thetransmitter 1120 may be an example of aspects of the transceiver 1335described with reference to FIG. 13. The transmitter 1120 may utilize asingle antenna or a set of antennas.

FIG. 12 shows a block diagram 1200 of a decoder polar coding module 1215that supports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure. Thedecoder polar coding module 1215 may be an example of aspects of adecoder polar coding module described with reference to FIGS. 10, 11,and 13. The decoder polar coding module 1215 may include receptioncomponent 1220, polar decoding component 1225, payload sizedetermination component 1230, bit vector parser 1235, de-scramblingcomponent 1240, parity check component 1245, indicator bit identifier1250, and bit vector modifier 1255. Each of these modules maycommunicate, directly or indirectly, with one another (e.g., via one ormore buses).

Reception component 1220 may receive a polar-encoded codeword, thecodeword generated based on a bit vector including a set of payload bitsof a payload.

Polar decoding component 1225 may perform a blind decoding process onthe codeword. For example, polar decoding component 1225 may decode thecodeword to obtain the bit vector based on the determined size of thepayload.

Payload size determination component 1230 may determine a size of thepayload based on at least one LLR associated with the bit vector. Bitvector parser 1235 may parse the bit vector to obtain the set of payloadbits based on the determined size of the payload.

De-scrambling component 1240 may perform one or more de-scramblingoperations on at least one bit decision for the at least one LLR, whereeach de-scrambling operation utilizes a masking vector corresponding toa payload size. In some cases, de-scrambling component 1240 may identifya successful de-scrambling operation based on comparing a set ofde-scrambled parity bits to a set of de-scrambled payload bits, and maydetermine the size of the payload as the payload size corresponding tothe masking vector for the successful de-scrambling operation. In somecases, the de-scrambling operation includes an inverse XOR operation.

In some cases, the codeword is further generated based on a set ofparity bits, where the set of payload bits and the set of parity bitsare assigned to a set of information bit channels. In these cases,determining the size of the payload may include parity check component1245 performing one or more parity checks on at least one bit decisionfor the at least one LLR using the set of parity bits, where apositioning of the set of parity bits within the codeword for eachparity check indicates a corresponding payload size. In some cases,parity check component 1245 may identify a successful parity check basedon the set of parity bits and the at least one bit decision for the atleast one LLR, and may determine the size of the payload as thecorresponding payload size indicated by the positioning of the set ofparity bits resulting in the successful parity check. In some cases, atleast one bit of the set of parity bits is assigned to a least reliablechannel of the set of information bit channels. In some cases, the setof parity bits includes a set of CRC bits.

In some cases, determining the size of the payload includes indicatorbit identifier 1250 identifying a least reliable bit channel of thecodeword with an LLR indicating an opposite bit value to a defaultfrozen bit value. Indicator bit identifier 1250 may determine the sizeof the payload based on the identified least reliable bit channel.

In some cases, bit vector modifier 1255 may remove an initial bitcorresponding to the LLR indicating the opposite bit value to thedefault frozen bit value. In other cases, bit vector modifier 1255 mayreorder bits of the bit vector based on the LLR indicating the oppositebit value to the default frozen bit value.

FIG. 13 shows a block diagram of a system 1300 including a device 1305that supports polar coding techniques for blind detection of differentpayload sizes in accordance with aspects of the present disclosure.Device 1305 may be an example of or include the components of wirelessdevice 1005, wireless device 1105, a base station 105, a UE 115, or adecoder as described above, e.g., with reference to FIGS. 1, 2, 10, and11. Device 1305 may include components for bi-directional voice and datacommunications including components for transmitting and receivingcommunications, including decoder polar coding module 1315, processor1320, memory 1325, software 1330, transceiver 1335, and I/O controller1340. These components may be in electronic communication via one ormore buses (e.g., bus 1310).

Processor 1320 may include an intelligent hardware device, (e.g., ageneral-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, anFPGA, a programmable logic device, a discrete gate or transistor logiccomponent, a discrete hardware component, or any combination thereof).In some cases, processor 1320 may be configured to operate a memoryarray using a memory controller. In other cases, a memory controller maybe integrated into processor 1320. Processor 1320 may be configured toexecute computer-readable instructions stored in a memory to performvarious functions (e.g., functions or tasks supporting polar codingtechniques for blind detection of different payload sizes).

Memory 1325 may include RAM and ROM. The memory 1325 may storecomputer-readable, computer-executable software 1330 includinginstructions that, when executed, cause the processor to perform variousfunctions described herein. In some cases, the memory 1325 may contain,among other things, a BIOS which may control basic hardware or softwareoperation such as the interaction with peripheral components or devices.

Software 1330 may include code to implement aspects of the presentdisclosure, including code to support polar coding techniques for blinddetection of different payload sizes. Software 1330 may be stored in anon-transitory computer-readable medium such as system memory or othermemory. In some cases, the software 1330 may not be directly executableby the processor but may cause a computer (e.g., when compiled andexecuted) to perform functions described herein.

Transceiver 1335 may communicate bi-directionally, via one or moreantennas, wired, or wireless links as described above. For example, thetransceiver 1335 may represent a wireless transceiver and maycommunicate bi-directionally with another wireless transceiver. Thetransceiver 1335 may also include a modem to modulate the packets andprovide the modulated packets to the antennas for transmission, and todemodulate packets received from the antennas.

I/O controller 1340 may manage input and output signals for device 1305.I/O controller 1340 may also manage peripherals not integrated intodevice 1305. In some cases, I/O controller 1340 may represent a physicalconnection or port to an external peripheral. In some cases, I/Ocontroller 1340 may utilize an operating system such as iOS®, ANDROID®,MS-DOS®, MS-WINDOWS®, OO/2®, UNIX®, LINUX®, or another known operatingsystem. In other cases, I/O controller 1340 may represent or interactwith a modem, a keyboard, a mouse, a touchscreen, or a similar device.In some cases, I/O controller 1340 may be implemented as part of aprocessor. In some cases, a user may interact with device 1305 via I/Ocontroller 1340 or via hardware components controlled by I/O controller1340.

FIG. 14 shows a flowchart illustrating a method 1400 for polar codingtechniques for blind detection of different payload sizes in accordancewith aspects of the present disclosure. The operations of method 1400may be implemented by an encoder or its components as described herein.The encoder may be a component of a wireless device, such as a basestation 105 or a UE 115. For example, the operations of method 1400 maybe performed by an encoder polar coding module as described withreference to FIGS. 6 through 9. In some examples, an encoder may executea set of codes to control the functional elements of the device toperform the functions described below. Additionally or alternatively,the encoder may perform aspects of the functions described below usingspecial-purpose hardware.

At 1405 the encoder may identify a plurality of payload bits of apayload for encoding. The operations of 1405 may be performed accordingto the methods described herein. In certain examples, aspects of theoperations of 1405 may be performed by a payload component as describedwith reference to FIGS. 6 through 9.

At 1410 the encoder may determine a bit vector comprising the pluralityof payload bits, wherein at least one bit or a bit order of the bitvector is based at least in part on a size of the payload. Theoperations of 1410 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1410 may beperformed by a bit vector component as described with reference to FIGS.6 through 9.

At 1415 the encoder may generate a polar-encoded codeword based at leastin part on the bit vector. The operations of 1415 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations of 1415 may be performed by a polar encoding componentas described with reference to FIGS. 6 through 9.

At 1420 the encoder may transmit the polar-encoded codeword. Theoperations of 1420 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1420 may beperformed by a transmission component as described with reference toFIGS. 6 through 9.

FIG. 15 shows a flowchart illustrating a method 1500 for polar codingtechniques for blind detection of different payload sizes in accordancewith aspects of the present disclosure. The operations of method 1500may be implemented by an encoder or its components as described herein.The encoder may be a component of a wireless device, such as a basestation 105 or a UE 115. For example, the operations of method 1500 maybe performed by an encoder polar coding module as described withreference to FIGS. 6 through 9. In some examples, an encoder may executea set of codes to control the functional elements of the device toperform the functions described below. Additionally or alternatively,the encoder may perform aspects of the functions described below usingspecial-purpose hardware.

At 1505 the encoder may identify a plurality of payload bits of apayload for encoding. The operations of 1505 may be performed accordingto the methods described herein. In certain examples, aspects of theoperations of 1505 may be performed by a payload component as describedwith reference to FIGS. 6 through 9.

At 1510 the encoder may determine a bit vector comprising the pluralityof payload bits, wherein at least one bit or a bit order of the bitvector is based at least in part on a size of the payload. Theoperations of 1510 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1510 may beperformed by a bit vector component as described with reference to FIGS.6 through 9.

At 1515 the encoder may determine a masking vector corresponding to thesize of the payload. The operations of 1515 may be performed accordingto the methods described herein. In certain examples, aspects of theoperations of 1515 may be performed by a masking component as describedwith reference to FIGS. 6 through 9.

At 1520 the encoder may scramble the plurality of payload bits, aplurality of parity bits associated with the plurality of payload bits,a plurality of frozen bits, or a combination thereof with the maskingvector. The operations of 1520 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 1520may be performed by a masking component as described with reference toFIGS. 6 through 9.

At 1525 the encoder may generate a polar-encoded codeword based at leastin part on the bit vector. The operations of 1525 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations of 1525 may be performed by a polar encoding componentas described with reference to FIGS. 6 through 9.

At 1530 the encoder may transmit the polar-encoded codeword. Theoperations of 1530 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1530 may beperformed by a transmission component as described with reference toFIGS. 6 through 9.

FIG. 16 shows a flowchart illustrating a method 1600 for polar codingtechniques for blind detection of different payload sizes in accordancewith aspects of the present disclosure. The operations of method 1600may be implemented by an encoder or its components as described herein.The encoder may be a component of a wireless device, such as a basestation 105 or a UE 115. For example, the operations of method 1600 maybe performed by an encoder polar coding module as described withreference to FIGS. 6 through 9. In some examples, an encoder may executea set of codes to control the functional elements of the device toperform the functions described below. Additionally or alternatively,the encoder may perform aspects of the functions described below usingspecial-purpose hardware.

At 1605 the encoder may identify a plurality of payload bits of apayload for encoding. The operations of 1605 may be performed accordingto the methods described herein. In certain examples, aspects of theoperations of 1605 may be performed by a payload component as describedwith reference to FIGS. 6 through 9.

At 1610 the encoder may determine a bit vector comprising the pluralityof payload bits and a plurality of parity bits associated with thepayload bits, wherein at least one bit or a bit order of the bit vectoris based at least in part on a size of the payload. The operations of1610 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 1610 may be performed bya bit vector component as described with reference to FIGS. 6 through 9.

At 1615 the encoder may position at least one bit of the plurality ofparity bits in a lowest index of the bit vector, wherein the pluralityof payload bits are positioned in higher indices of the bit vector. Theoperations of 1615 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1615 may beperformed by a parity bit front-loading component as described withreference to FIGS. 6 through 9.

At 1620 the encoder may generate a polar-encoded codeword based at leastin part on the bit vector. The operations of 1620 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations of 1620 may be performed by a polar encoding componentas described with reference to FIGS. 6 through 9.

At 1625 the encoder may transmit the polar-encoded codeword. Theoperations of 1625 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1625 may beperformed by a transmission component as described with reference toFIGS. 6 through 9.

FIG. 17 shows a flowchart illustrating a method 1700 for polar codingtechniques for blind detection of different payload sizes in accordancewith aspects of the present disclosure. The operations of method 1700may be implemented by an encoder or its components as described herein.The encoder may be a component of a wireless device, such as a basestation 105 or a UE 115. For example, the operations of method 1700 maybe performed by an encoder polar coding module as described withreference to FIGS. 6 through 9. In some examples, an encoder may executea set of codes to control the functional elements of the device toperform the functions described below. Additionally or alternatively,the encoder may perform aspects of the functions described below usingspecial-purpose hardware.

At 1705 the encoder may identify a plurality of payload bits of apayload for encoding. The operations of 1705 may be performed accordingto the methods described herein. In certain examples, aspects of theoperations of 1705 may be performed by a payload component as describedwith reference to FIGS. 6 through 9.

At 1710 the encoder may determine a bit vector comprising the pluralityof payload bits, wherein at least one bit or a bit order of the bitvector is based at least in part on a size of the payload. Theoperations of 1710 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1710 may beperformed by a bit vector component as described with reference to FIGS.6 through 9.

At 1715 the encoder may append an initial bit to the bit vector, whereinthe initial bit comprises an opposite bit value to a default frozen bitvalue. The operations of 1715 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 1715may be performed by an indicator bit component as described withreference to FIGS. 6 through 9.

At 1720 the encoder may generate a polar-encoded codeword based at leastin part on the bit vector. The operations of 1720 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations of 1720 may be performed by a polar encoding componentas described with reference to FIGS. 6 through 9.

At 1725 the encoder may transmit the polar-encoded codeword. Theoperations of 1725 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1725 may beperformed by a transmission component as described with reference toFIGS. 6 through 9.

FIG. 18 shows a flowchart illustrating a method 1800 for polar codingtechniques for blind detection of different payload sizes in accordancewith aspects of the present disclosure. The operations of method 1800may be implemented by an encoder or its components as described herein.The encoder may be a component of a wireless device, such as a basestation 105 or a UE 115. For example, the operations of method 1800 maybe performed by an encoder polar coding module as described withreference to FIGS. 6 through 9. In some examples, an encoder may executea set of codes to control the functional elements of the device toperform the functions described below. Additionally or alternatively,the encoder may perform aspects of the functions described below usingspecial-purpose hardware.

At 1805 the encoder may identify a plurality of payload bits of apayload for encoding. The operations of 1805 may be performed accordingto the methods described herein. In certain examples, aspects of theoperations of 1805 may be performed by a payload component as describedwith reference to FIGS. 6 through 9.

At 1810 the encoder may determine a bit vector comprising the pluralityof payload bits, wherein at least one bit or a bit order of the bitvector is based at least in part on a size of the payload. Theoperations of 1810 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1810 may beperformed by a bit vector component as described with reference to FIGS.6 through 9.

At 1815 the encoder may arrange the plurality of payload bits, aplurality of parity bits associated with the plurality of payload bits,a plurality of frozen bits, or a combination thereof so that an initialbit of the bit vector comprises an opposite bit value to a defaultfrozen bit value. The operations of 1815 may be performed according tothe methods described herein. In certain examples, aspects of theoperations of 1815 may be performed by a bit vector arranging componentas described with reference to FIGS. 6 through 9.

At 1820 the encoder may generate a polar-encoded codeword based at leastin part on the bit vector. The operations of 1820 may be performedaccording to the methods described herein. In certain examples, aspectsof the operations of 1820 may be performed by a polar encoding componentas described with reference to FIGS. 6 through 9.

At 1825 the encoder may transmit the polar-encoded codeword. Theoperations of 1825 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1825 may beperformed by a transmission component as described with reference toFIGS. 6 through 9.

FIG. 19 shows a flowchart illustrating a method 1900 for polar codingtechniques for blind detection of different payload sizes in accordancewith aspects of the present disclosure. The operations of method 1900may be implemented by a decoder or its components as described herein.The decoder may be a component of a wireless device, such as a basestation 105 or a UE 115. For example, the operations of method 1900 maybe performed by a decoder polar coding module as described withreference to FIGS. 10 through 13. In some examples, a decoder mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the decoder may perform aspects of the functions described below usingspecial-purpose hardware.

At 1905 the decoder may receive a polar-encoded codeword, thepolar-encoded codeword generated based at least in part on a bit vectorcomprising a plurality of payload bits of a payload. The operations of1905 may be performed according to the methods described herein. Incertain examples, aspects of the operations of 1905 may be performed bya reception component as described with reference to FIGS. 10 through13.

At 1910 the decoder may perform a blind decoding process on thepolar-encoded codeword. In some cases, the blind decoding process mayinclude the determining, decoding and parsing steps described below. Theoperations of 1910 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1910 may beperformed by a polar decoding component as described with reference toFIGS. 10 through 13.

At 1915 the decoder may determine a size of the payload based at leastin part on at least one LLR associated with the bit vector. Theoperations of 1915 may be performed according to the methods describedherein. In certain examples, aspects of the operations of 1915 may beperformed by a payload size determination component as described withreference to FIGS. 10 through 13.

At 1920 the decoder may decode the polar-encoded codeword to obtain thebit vector based at least in part on the determined size of the payload.The operations of 1920 may be performed according to the methodsdescribed herein. In certain examples, aspects of the operations of 1920may be performed by a polar decoding component as described withreference to FIGS. 10 through 13.

At 1925 the decoder may parse the bit vector to obtain the plurality ofpayload bits based at least in part on the determined size of thepayload. The operations of 1925 may be performed according to themethods described herein. In certain examples, aspects of the operationsof 1925 may be performed by a bit vector parser as described withreference to FIGS. 10 through 13.

In some examples, aspects from two or more of the described methods maybe combined. It should be noted that the described methods are justexample implementations, and that the operations of the describedmethods may be rearranged or otherwise modified such that otherimplementations are possible.

Techniques described herein may be used for various wirelesscommunications systems such as code division multiple access (CDMA),time division multiple access (TDMA), frequency division multiple access(FDMA), orthogonal FDMA (OFDMA), single carrier frequency divisionmultiple access (SC-FDMA), and other systems. A CDMA system mayimplement a radio technology such as CDMA2000, UTRA, etc. CDMA2000covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases may becommonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) iscommonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD),etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. ATDMA system may implement a radio technology such as Global System forMobile Communications (GSM).

An OFDMA system may implement a radio technology such as Ultra MobileBroadband (UMB), E-UTRA, Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20,Flash-OFDM, etc. UTRA and E-UTRA are part of Universal MobileTelecommunications System (UMTS). LTE and LTE-A are releases of UMTSthat use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, NR, and GSM aredescribed in documents from the organization named “3rd GenerationPartnership Project” (3GPP). CDMA2000 and UMB are described in documentsfrom an organization named “3rd Generation Partnership Project 2”(3GPP2). The techniques described herein may be used for the systems andradio technologies mentioned above as well as other systems and radiotechnologies. While aspects of an LTE or an NR system may be describedfor purposes of example, and LTE or NR terminology may be used in muchof the description, the techniques described herein are applicablebeyond LTE or NR applications.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEs115 with service subscriptions with the network provider. A small cellmay be associated with a lower-powered base station 105, as comparedwith a macro cell, and a small cell may operate in the same or different(e.g., licensed, unlicensed, etc.) frequency bands as macro cells. Smallcells may include pico cells, femto cells, and micro cells according tovarious examples. A pico cell, for example, may cover a small geographicarea and may allow unrestricted access by UEs 115 with servicesubscriptions with the network provider. A femto cell may also cover asmall geographic area (e.g., a home) and may provide restricted accessby UEs 115 having an association with the femto cell (e.g., UEs 115 in aclosed subscriber group (CSG), UEs 115 for users in the home, and thelike). An eNB for a macro cell may be referred to as a macro eNB. An eNBfor a small cell may be referred to as a small cell eNB, a pico eNB, afemto eNB, or a home eNB. An eNB may support one or multiple (e.g., two,three, four, and the like) cells, and may also support communicationsusing one or multiple component carriers.

The wireless communications system 100 or systems described herein maysupport synchronous or asynchronous operation. For synchronousoperation, the base stations 105 may have similar frame timing, andtransmissions from different base stations 105 may be approximatelyaligned in time. For asynchronous operation, the base stations 105 mayhave different frame timing, and transmissions from different basestations 105 may not be aligned in time. The techniques described hereinmay be used for either synchronous or asynchronous operations.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, a FPGA or other programmablelogic device (PLD), discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices (e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope and spirit of the disclosure and appended claims. For example,due to the nature of software, functions described above can beimplemented using software executed by a processor, hardware, firmware,hardwiring, or combinations of any of these. Features implementingfunctions may be physically located at various positions, includingbeing distributed such that portions of functions are implemented atdifferent physical locations.

As used herein, including in the claims, the term “and/or,” when used ina list of two or more items, means that any one of the listed items canbe employed by itself, or any combination of two or more of the listeditems can be employed. For example, if a composition is described ascontaining components A, B, and/or C, the composition can contain Aalone; B alone; C alone; A and B in combination; A and C in combination;B and C in combination; or A, B, and C in combination. Also, as usedherein, including in the claims, “or” as used in a list of items (forexample, a list of items prefaced by a phrase such as “at least one of”or “one or more of”) indicates an inclusive list such that, for example,a phrase referring to “at least one of” a list of items refers to anycombination of those items, including single members. As an example, “atleast one of: A, B, or C” is intended to cover A, B, C, A-B, A-C, B-C,and A-B-C, as well as any combination with multiples of the same element(e.g., A-A A-A-A, A-A-B, A-A-C, A-B-B, A-C-C, B-B, B-B-B, B-B-C, C-C,and C-C-C or any other ordering of A, B, and C).

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media cancomprise RAM, ROM, electrically erasable programmable read only memory(EEPROM), compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that can be used to carry or store desired programcode means in the form of instructions or data structures and that canbe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, DSL, orwireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include CD, laser disc, optical disc, digital versatile disc (DVD),floppy disk and Blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

As used herein, the phrase “based on” shall not be construed as areference to a closed set of conditions. For example, an exemplaryfeature that is described as “based on condition A” may be based on botha condition A and a condition B without departing from the scope of thepresent disclosure. In other words, as used herein, the phrase “basedon” shall be construed in the same manner as the phrase “based at leastin part on.”

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, well-known structures and devices are shownin block diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notlimited to the examples and designs described herein, but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

1. A method for wireless communication, comprising: identifying aplurality of payload bits of a payload for encoding; determining a bitvector comprising the plurality of payload bits, wherein at least onebit or a bit order of the bit vector is based at least in part on a sizeof the payload; generating a polar-encoded codeword based at least inpart on the bit vector; and transmitting the polar-encoded codeword. 2.The method of claim 1, further comprising: determining a masking vectorcorresponding to the size of the payload; and scrambling the pluralityof payload bits, a plurality of parity bits associated with theplurality of payload hits, a plurality of frozen bits, or a combinationthereof with the masking vector.
 3. The method of claim 2, whereinscrambling the plurality of payload bits, the plurality of parity bits,the plurality of frozen bits, or the combination thereof with themasking vector comprises an exclusive or (XOR) operation.
 4. The methodof claim 1, wherein the bit vector comprises the plurality of payloadbits and a plurality of parity bits associated with the plurality ofpayload bits.
 5. The method of claim 4, wherein determining the bitvector comprises: positioning at least one bit of the plurality ofparity bits in a lowest index of the bit vector, wherein the pluralityof payload bits are positioned in higher indices of the bit vector. 6.method of claim 5, wherein generating the polar-encoded codewordcomprises: assigning the plurality of payload bits and the plurality ofparity bits to a plurality of information bit channels of a polar code,wherein the at least one bit of the plurality of parity bits is assignedto a least reliable channel of the plurality of information bitchannels.
 7. The method of claim 4, further comprising: applying aparity function to the plurality of payload bits to generate theplurality of parity bits.
 8. The method of claim 4, wherein theplurality of parity bits comprises a plurality of cyclic redundancycheck (CRC) bits.
 9. The method of claim 1, wherein determining the bitvector comprises: appending an initial bit to the bit vector, whereinthe initial bit comprises an opposite bit value to a default frozen bitvalue.
 10. The method of claim 9, wherein the initial bit indicates amessage type associated with the payload.
 11. The method of claim 1,wherein determining the hit vector comprises: arranging the plurality ofpayload bits, a plurality of parity bits associated with the pluralityof payload bits, a plurality of frozen bits, or a combination thereof sothat an initial bit of the bit vector comprises an opposite bit value toa default frozen bit value.
 12. A method for wireless communication,comprising: receiving a polar-encoded codeword, the polar-encodedcodeword generated based at least in part on a bit vector comprising aplurality of payload bits of a payload; and performing a blind decodingprocess on the polar-encoded codeword, the blind decoding processcomprising: determining a size of the payload based at least in part onat least one log-likelihood ratio (LLR) associated with the bit vector;decoding the polar-encoded codeword to obtain the bit vector based atleast in part on the determined size of the payload; and parsing the bitvector to obtain the plurality of payload bits based at least in part onthe determined size of the payload.
 13. The method of claim 12, whereindetermining the size of the payload comprises: performing one or morede-scrambling operations on at least one bit decision for the at leastone LLR, wherein each de-scrambling operation utilizes a masking vectorcorresponding to a payload size.
 14. The method of claim 13, furthercomprising: identifying a successful de-scrambling operation based atleast in part on comparing a plurality of de-scrambled parity bits to aplurality of de-scrambled payload bits; and determining the size of thepayload as the payload size corresponding to the masking vector for thesuccessful de-scrambling operation.
 15. The method of claim 13, thede-scrambling operation comprises an inverse exclusive or (XOR)operation.
 16. The method of claim 12, wherein the polar-encodedcodeword is further generated based at least in part on a plurality ofparity bits, the plurality of payload bits and the plurality of paritybits assigned to a plurality of information bit channels, anddetermining the size of the payload comprises: performing one or moreparity checks on at least one bit decision for the at least one LLRusing the plurality of parity bits, wherein a positioning of theplurality of parity bits within the polar-encoded codeword for eachparity check indicates a corresponding payload size.
 17. The method ofclaim 16, further comprising: identifying a successful parity checkbased at least in part on the plurality of parity bits and the at leastone bit decision for the at least one LLR; and determining the size ofthe payload as the corresponding payload size indicated by thepositioning of the plurality of parity bits resulting in the successfulparity check.
 18. The method of claim 16, wherein at least one bit ofthe plurality of parity bits is assigned to a least reliable channel ofthe plurality of information bit channels.
 19. The method of claim 16,wherein the plurality of parity bits comprises a plurality of cyclicredundancy check (CRC) bits.
 20. The method of claim 12, whereindetermining the size of the payload comprises: identifying a leastreliable bit channel of the polar-encoded codeword with an LLRindicating an opposite bit value to a default frozen bit value; anddetermining the size of the payload based at least in part on theidentified least reliable bit channel.
 21. The method of claim 20,wherein parsing the bit vector comprises: removing an initial bitcorresponding to the LLR indicating the opposite bit value to thedefault frozen bit value.
 22. The method of claim 20, wherein parsingthe bit vector comprises: reordering bits of the bit vector based atleast in part on the LLR indicating the opposite bit value to thedefault frozen bit value. 23-44. (canceled)
 45. An apparatus forwireless communication, comprising: a processor; memory in electroniccommunication with the processor; and instructions stored in the memoryand executable by the processor to cause the apparatus to: identify aplurality of payload bits of a payload for encoding; determine a bitvector comprising the plurality of payload bits, wherein at least onebit or a bit order of the bit vector is based at least in part on a sizeof the payload; generate a polar-encoded codeword based at least in parton the bit vector; and transmit the polar-encoded codeword.
 46. Theapparatus of claim 45, wherein the instructions are further executableby the processor to cause the apparatus to: determine a masking vectorcorresponding to the size of the payload; and scramble the plurality ofpayload bits, a plurality of parity bits associated with the pluralityof payload bits, a plurality of frozen bits, or a combination thereofwith the masking vector.
 47. The apparatus of claim 46, whereinscrambling the plurality of payload hits, the plurality of parity bits,the plurality of frozen bits, or the combination thereof with themasking vector comprises an exclusive or (XOR) operation.
 48. Theapparatus of claim 4, wherein the bit vector comprises the plurality ofpayload bits and a plurality of parity bits associated with theplurality of payload bits.
 49. The apparatus of claim 48, wherein theinstructions to determine the bit vector are executable by the processorto cause the apparatus to: position at least one bit of the plurality ofparity bits in a lowest index of the bit vector, wherein the pluralityof payload bits are positioned in higher indices of the bit vector. 50.The apparatus of claim 49, wherein the instructions to generate thepolar-encoded codeword are executable by the processor to cause theapparatus to: assign the plurality of payload bits and the plurality ofparity bits to a plurality of information bit channels of a polar code,wherein the at least one bit of the plurality of parity bits is assignedto a least reliable channel of the plurality of information bitchannels.
 51. The apparatus of claim 48, wherein the instructions arefurther executable by the processor to cause the apparatus to: apply aparity function to the plurality of payload hits to generate theplurality of parity bits.
 52. The apparatus of claim 48, wherein theplurality of parity bits comprises a plurality of cyclic redundancycheck (CRC) bits.
 53. The apparatus of claim 45, wherein theinstructions to determine the bit vector are executable by the processorto cause the apparatus to: append an initial bit to the bit vector,wherein the initial bit comprises an opposite bit value to a defaultfrozen bit value.
 54. The apparatus of claim
 53. wherein the initial bitindicates a message type associated with the payload.
 55. The apparatusof claim 45 wherein the instructions to determine the bit vector areexecutable by the processor to cause the apparatus to: arrange theplurality of payload bits, a plurality of parity bits associated withthe plurality of payload bits, a plurality of frozen bits, or acombination thereof so that an initial bit of the bit vector comprisesan opposite bit value to a default frozen bit value.
 56. An apparatusfor wireless communication, comprising: a processor; memory inelectronic communication with the processor; and instructions stored inthe memory and executable by the processor to cause the apparatus to:receive a polar-encoded codeword, the polar-encoded codeword generatedbased at least in part on a bit vector comprising a plurality of payloadbits of a payload; and perform a blind decoding process on thepolar-encoded codeword, the instructions stored in the memory for theblind decoding process executable by the processor to cause theapparatus to: determine a size of the payload based at least in part onat least one log-likelihood ratio (LLR) associated with the bit vector;decode the polar-encoded codeword to obtain the bit vector based atleast in part on the determined size of the payload; and parse the bitvector to obtain the plurality of payload bits based at least in part onthe determined size of the payload.
 57. The apparatus of claim 56,wherein the instructions to determine the size of the payload areexecutable by the processor to cause the apparatus to: perform one ormore de-scrambling operations on at least one bit decision for the atleast one LLR, wherein each de-scrambling operation utilizes a maskingvector corresponding to a payload size.
 58. The apparatus of claim 57,wherein the instructions are further executable by the processor tocause the apparatus to: identify a successful de-scrambling operationbased at least in part on comparing a plurality of de-scrambled paritybits to a plurality of de-scrambled payload bits; and determine the sizeof the payload as the payload size corresponding to the masking vectorfor the successful de-scrambling operation.
 59. The apparatus of claim57, wherein the de-scrambling operation comprises an inverse exclusiveor (XOR) operation.
 60. The apparatus of claim 56, wherein theinstructions to the polar-encoded codeword is further generated based atleast in part on a plurality of parity bits, the plurality of payloadbits and the plurality of parity bits assigned to a plurality ofinformation bit channels, and determining the size of the payload areexecutable by the processor to cause the apparatus to: perform one ormore parity checks on at least one bit decision for the at least one LLRusing the plurality of parity bits, wherein a positioning of theplurality of parity bits within the polar-encoded codeword for eachparity check indicates a corresponding payload size.
 61. The apparatusof claim 60, wherein the instructions are further executable by theprocessor to cause the apparatus to: identify a successful parity checkbased at least in part on the plurality of parity bits and the at leastone bit decision for the at least one LLR; and determine the size of thepayload as the corresponding payload size indicated by the positioningof the plurality of parity bits resulting in the successful paritycheck.
 62. The apparatus of claim 60, wherein at least one bit of theplurality of parity bits is assigned to a least reliable channel of theplurality of information bit channels.
 63. The apparatus of claim 60,wherein the plurality of parity bits comprises a plurality of cyclicredundancy check (CRC) bits.
 64. The apparatus of claim 56, wherein theinstructions to determine the size of the payload are executable by theprocessor to cause the apparatus to: identify a least reliable bitchannel of the polar-encoded codeword with an LLR indicating an oppositebit value to a default frozen bit value; and determine the size of thepayload based at least in part on the identified least reliable hitchannel.
 65. The apparatus of claim 64, wherein the instructions toparse the bit vector are executable by the processor to cause theapparatus to: remove an initial bit corresponding to the LLR indicatingthe opposite bit value to the default frozen bit value.
 66. Theapparatus of claim 64, wherein the instructions to parse the bit vectorare executable by the processor to cause the apparatus to: reorder bitsof the bit vector based at least in part on the LLR indicating theopposite bit value to the default frozen bit value. 67-88. (canceled)